Plaintiff Joseph A. Morinelli appeals as of right the judgment entered following a jury trial in this action to enforce two disability insurance policies. Plaintiff Perfusion Associates of Michigan, Inc. (pam), appeals as of right the trial court’s order granting summary disposition in favor of defendant Provident Life and Accident Insurance Company. We reverse in part, affirm in part, and remand.
i
Plaintiff Morinelli is a perfusionist, which is the individual who operates the heart-lung machine, as well as other equipment, to keep a patient alive during open-heart surgery. In April 1990, Morinelli and his partners formed PAM. One year later, they purchased two policies of insurance from defendant: a disability income policy, which personally insured Morinelli in the event he suffered a loss resulting from injury or sickness, and a business buy-out expense disability policy, which insured PAM for any expenses attributable to a buy-sell agreement between the corporation and Morinelli if he ever became totally disabled.
Under the disability income policy, “total disability” is defined as follows:
Total Disability and totally disabled means that due to Injuries or Sickness, the Insured:
*2581. is not able to perform the substantial and material duties of his/her occupation; and
2. is receiving care by a Physician which is appropriate for the condition causing the disability. We will waive this requirement when continued care would be of no benefit to the Insured.
In July 1993, Dr. Eugene Calabrese examined Morinelli and diagnosed him as having diabetes. Dr. Calabrese prescribed Glucotrol, an oral medication designed to reduce blood sugar levels, a diet, and exercise. Over time, the Glucotrol was adjusted to the maximum recommended dosage, and, by September 1994, Morinelli needed insulin injections to control the diabetes. At the timé, Morinelli was experiencing fatigue, forgetfulness, and frequent urination, all of which compromised his ability to perform as a perfusionist.
On October 24, 1994, Morinelli filed a disability claim, which was supported by Dr. Calabrese’s opinion that he was totally disabled. Defendant began paying benefits under its disability income policy, but later terminated the payments, asserting (1) that Morinelli’s diabetes had first manifested itself before the issuance of the insurance policies, and (2) that diabetes did not appear to impair his ability to perform the material and substantial duties of his occupation in that the claim was based on an assumption that a diabetic incident would arise and did not allege that Morinelli was unable to perform his duties absent such an incident. The plaintiffs subsequently filed this action asserting breach of contract, as well as other claims not germane to this appeal.
The trial court granted defendant’s motion for summary disposition, which sought to rescind the buy-out *259expense disability policy because, contrary to representations in the application for insurance, no written agreement existed between PAM, or its principals, and Morinelli. The court found that PAM failed to meet a condition precedent for the payment of benefits under the terms of the policy in that there was no buy-sell agreement in place until after either of the plaintiffs had filed a claim.
At trial, defendant presented evidence concerning the quality of the treatment rendered by Dr. Calabrese. Standard of care testimony was admitted over Morinelli’s objection. As specified on the verdict form, the jury found that Morinelli “suffered from a sickness, to wit: diabetes, from June 23, 1995, to the present, that has prevented him from performing the substantial and material duties of his occupation as a perfusionist.” The jury did not find that Morinelli “received care by a physician that was appropriate for the condition of diabetes.”
The court denied Morinelli’s motion for judgment notwithstanding the verdict (JNOV) on the basis of its finding that the evidence was sufficient to support the verdict in that the definition of “total disability” included a finding of “appropriate care.” The court ruled that Morinelli could not claim surprise because defendant had raised the issue in its affirmative defenses,1 in its response to interrogatories,2 and in *260its opening statements.3 Moreover, Morinelli did not raise the issue of the meaning of the phrase “appropriate care” until after the verdict. The court also denied Morinelli’s motion for a new trial on the basis of its finding that the policy language was unambiguous. The meaning of the word “appropriate” as used in the policy’s medical care clause forms the crux of this appeal.
n
Morinelli (hereafter plaintiff) first argues that the defendant’s allegation that the care received by plaintiff was inappropriate in that it did not meet the standard of care was not a proper contractual defense to his claim for disability benefits. Plaintiff argues that the treatment he received for his diabetes was appropriate for the condition and, therefore, met the clear language of the policy. We agree.
We review a trial court’s decision with regard to a motion for jnov de novo. Meagher v Wayne State Univ, 222 Mich App 700, 721; 565 NW2d 401 (1997). In reviewing a decision regarding a motion for jnov, this Court must view the testimony and all legitimate inferences that may be drawn therefrom in a light most favorable to the nonmoving party. Forge v Smith, 458 Mich 198, 204; 580 NW2d 876 (1998). If reasonable jurors could have honestly reached difier*261ent conclusions, the jury verdict must stand. Severn v Sperry Corp, 212 Mich App 406, 412; 538 NW2d 50 (1995). The interpretation of contractual language is an issue of law that is also reviewed de novo on appeal. Morley v Automobile Club of Michigan, 458 Mich 459, 465; 581 NW2d 237 (1998).
In deciding a motion for a new trial, the trial court’s function is to determine whether the overwhelming weight of the evidence favors the losing party. Phinney v Perlmutter, 222 Mich App 513, 525; 564 NW2d 532 (1997). This Court must determine whether the trial court abused its discretion in ruling with regard to a motion for a new trial. Id. Substantial deference is given to the trial court’s conclusion that the verdict was not against the great weight of the evidence. Id.
The purpose underlying a policy’s medical care clause is that of enabling the insurer to guard against fraudulent claims and to establish the good faith of the claimant. 10 Couch, Insurance, 3d, § 146:25, p 146-53. The insurer’s review of the nature of the care concerns whether it is “necessary and causally related” to the alleged disability. Id., p 146-54. Although the medical clause in this policy is under the definition of “total disability,” it is actually a requirement or a condition of coverage, and compliance with the condition is an issue distinct from that of the elements of total disability. Crosby v Prudence Mut Casualty Co, 252 SC 294; 166 SE2d 201 (1969).
An insurance policy is much the same as another contract; it is an agreement between the parties. Auto-Owners Ins Co v Churchman, 440 Mich 560, 566; 489 NW2d 431 (1992); Moore v First Security Casualty Co, 224 Mich App 370, 375; 568 NW2d 841 (1997). Any ambiguities in insurance contracts are *262liberally construed in favor of the insured and against the insurer, who drafted the contract. State Farm Mut Automobile Ins Co v Enterprise Leasing Co, 452 Mich 25, 38; 549 NW2d 345 (1996). This does not mean that the plain meaning of a word or phrase should be perverted, or that a word or phrase, the meaning of which is specific and well recognized, should be given some alien construction merely for the purpose of benefiting an insured. Upjohn Co v New Hampshire Ins Co, 438 Mich 197, 208, n 8; 476 NW2d 392 (1991). The fact that a policy does not define a relevant term does not render the policy ambiguous. Henderson v State Farm Fire & Casualty Co, 460 Mich 348, 354; 596 NW2d 190 (1999). This Court must interpret the terms of the contract in accordance with their commonly used meanings. Group Ins Co of Michigan v Czopek, 440 Mich 590, 596; 489 NW2d 444 (1992).
The policy at issue in this case does not define the word “appropriate,” and no Michigan case has interpreted language similar to that found in defendant’s disability policy. The court may refer to dictionary definitions when appropriate when ascertaining the precise meaning of a particular term. Popma v Auto Club Ins Ass’n, 446 Mich 460, 470; 521 NW2d 831 (1994). The word “appropriate” is defined as “particularly suitable; fitting; compatible.” Random House Webster’s College Dictionary (2d ed, 1997). Similarly, “appropriate” is defined as “[s]uitable for a particular person, condition, occasion, or place; proper; fitting.” The American Heritage Dictionary: Second College Edition (1985).
It is this Court’s opinion that the language found in the policy is not ambiguous and that “appropriate *263care” does not require a qualitative evaluation of the care provided. The policy does not state that to recover benefits under the policy, the insured must receive “appropriate care”; rather, the contract states that the care received must be “appropriate for the condition causing the disability.” Care “appropriate for the condition causing the disability” is care that is necessary and causally related to the condition forming the basis of the disability claim. It cannot be disputed that the insured in this case was receiving care from a licensed physician, acting within the scope of his license, that was appropriate to the treatment of diabetes (i.e., instruction on diet and exercise, periodic office visits, and the prescription of insulin). It was Dr. James LaFleur’s testimony and defense counsel's closing argument that cast specific doubt on the “appropriateness” of the care that Morinelii received. If this case involved a claim for medical malpractice, a determination of the standard of care and whether that standard was met would surely be in order. This case, however, involves an insured making a claim under his disability policy. As such, whether the level of treatment met the standard of care is not pertinent to a determination whether the care was appropriate.
Regardless of whether Morinelii had forewarning of defendant’s plan to argue standard of care issues, we deem the opinion testimony of Dr. LaFleur regarding the care rendered by Dr. Calabrese, as well as defendant’s arguments regarding the standard of care, to be beyond the scope of the issues to be decided in an action to enforce a disability insurance contract. Defendant’s expert witnesses testified that medication, diet control, and exercise are key elements in treating diabetes. Dr. George Grunberger stated in his *264deposition that he had no substantial complaint with how Dr. Calabrese treated Morinelli.4 Dr. Calabrese was treating Morinelli for his diabetes; the care was an appropriate regimen for the diabetic condition according to the parties and the experts.
Defendant is correct in its assertion that Morinelli had the burden of proving that he was disabled pursuant to the language of the policy. Forman v Prudential Ins Co of America, 310 Mich 145, 148; 16 NW2d 696 (1944). It is our opinion that Morinelli met that burden by showing not only that he was unable'to perform the substantial and material duties of a perfusionist, but also that he was receiving appropriate care for diabetes at the time the claim was filed. We hold that, in the context of this disability insurance dispute, the jury erred in concluding that the course of treatment Morinelli received was not appropriate care as contemplated by the policy.
III
Morinelli also argues that he was denied a fair trial by the admission, over his objection, of testimony concerning the quality of care rendered by Dr. Calabrese. We agree.
Dr. LaFleur was the last witness to testify. After reviewing Morinelli’s medical history and detailing fluctuations in his blood sugar levels and weight, defense counsel posed the following question to Dr. LaFleur:
*265Q: All right. Now, if you had a patient who had those levels of glycohemoglobin, and if there was a prescription for insulin on October 7, 1994, what would a — what would a — what would the appropriate course of treatment be over the course of time with regard to the glycohemoglobin, the insulin and diet?
Plaintiff objected on the ground that Dr. LaFleur’s expert testimony was inconsistent with that represented in defendant’s answer to Morinelli’s interrogatory regarding the scope of the opinions to be rendered by its experts. Specifically, plaintiff alleged that Dr. LaFleur’s testimony was given in violation of MCR 2.302(E)(l)(a)(ii), which states:
(E) Supplementation of Responses.
(1) Duty to Supplement. A party who has responded to a request for discovery with a response that was complete when made is under no duty to supplement the response to include information acquired later, except as follows:
(a) A party is under a duty seasonably to supplement the response with respect to a question directly addressed to
* * *
(ii) the identity of each person expected to be called as an expert witness at trial, the subject matter on which the expert is expected to testily, and the substance of the expert’s testimony.
It is within the trial court’s discretion to sanction a party for violating the discovery rules. MCR 2.302(E)(2). Likewise, .a trial court’s decision to admit evidence is reviewed for an abuse of discretion. Dep’t of Transportation v VanElslander, 460 Mich 127, 129; 594 NW2d 841 (1999). We find that the trial court abused its discretion in allowing Dr. LaFleur to *266testify regarding the quality of care received by Morinelli.5
Morinelli argued that, on the basis of defendant’s answer to the interrogatory regarding expert testimony, he did not consider it necessary to depose Dr. LaFleur because he had no idea the doctor would testify regarding the standard of care. As an offer of proof, Morinelli stated that he was unprepared to address criticism of Dr. Calabrese because there was no indication during discovery that defendant would suggest that Dr. Calabrese had fallen short of some undefined standard of care in treating Morinelli’s diabetes. The trial court agreed.
Nevertheless, Dr. LaFleur was allowed to testify regarding what treatment would have been successful in controlling Morinelli’s diabetes, and that with all the various testing methods and new drugs, there was no reason why Morinelli could not return to normal workday functions. The trial court attempted to rectify any perceived discrepancies between defendant’s interrogatory answer and Dr. LaFleur’s actual testimony. Dr. LaFleur was of the opinion that, if Morinelli maintained his blood sugar levels through proper insulin therapy, maintained a steady low-calorie diet, and took short breaks during long surgeries, he would be able to perform the duties of a perfusionist.
Although the quality of care testimony could arguably be considered relevant to the first prong of the *267definition of “total disability,” defense counsel’s closing argument made clear that the testimony was offered to show that the treatment did not meet the standard of care for diabetic patients. During closing argument, defendant’s counsel claimed that contrary to the recognized procedure for treating a diabetic patient’s blood sugar levels there had been “[t]otai neglect in the care and treatment of Mr. Morinelli’s weight problem.” He also stated: “The doctor’s not giving the right treatment. There’s something seriously wrong.”
Defendant’s counsel continued:
They think it’s okay. Dr. Calabrese thinks it’s okay to bring him down to 11 or 12 from 16 and send the man on his way. And it’s absurd. He’s killing the man. It’s absurd. It’s the most inappropriate care I’ve ever seen. He just — he just says, well, he’s gaming weight, and his levels have come down a little bit, so that’s fine. Doesn’t send him out for a consult, doesn’t change anything. It’s absurd.
Defendant’s counsel added comments that the chosen treatment was “absolutely, totally inappropriate.” He emphasized that the fact that the treatment was not succeeding in reducing Morinelli’s weight was evidence that “everything [Dr. Calabrese] was doing [was] totally inappropriate.” Morinelli did not object or seek a curative instruction.
Defendant argues that this appeal is actually a challenge to the jury instructions not properly before the Court because of Morinelli’s failure to object to the instructions We disagree. The pertinent instruction was given to the jury as follows:
The terms of the disability insurance policy control absent any ambiguity. In considering the definitions of *268terms contained in the disability insurance policy, you are to consider these definitions as they would be -understood by the ordinary business person or by a reasonable person in the place of the insured.
As instructed by the trial court, the jury was to give the terms of the policy their plain meaning. Looking at this instruction, we believe that Morinelli had no basis to challenge the instruction. Taken in the context of this lawsuit, it is clear that the word “appropriate” can mean only that Morinelli was being treated in a manner consistent with the usual course of treatment for diabetic conditions.
In support of his motion for jnov, Morinelli’s counsel stated that he “never conceived that this policy language could be invoked by the Defendant as a quality of care, as a medical malpractice standard.” Under the circumstances of this case, where Dr. LaFleur’s testimony was admitted over Morinelli’s objection, we find that Morinelli’s failure to request a curative instruction is not fatal to his appeal.
The jury’s finding that the care rendered by Dr. Calabrese was not appropriate leads us to the inescapable conclusion that the jurors agreed with defendant’s theory of the case — as presented by Dr. LaFleur’s testimony and in closing argument — that “appropriate care” as used in the policy meant treatment that meets the standard of care for physicians treating patients with diabetes. No evidence supported this conclusion other than the improperly admitted opinion testimony of Dr. LaFleur.
We find that the admission of the quality of care evidence was erroneous and prejudicial, and it injected into the case an issue that was not properly before the jury. Our determination that the second *269prong of the “totally disabled” definition does not entail an inquiry into whether the treatment met the standard of care supports a conclusion that the care rendered by Dr. Calabrese was appropriate, that is, necessary and causally related to Morinelli’s diabetic condition. The admission of Dr. LaFleur’s quality of care testimony constituted an abuse of discretion. We believe that, absent the improperly admitted testimony and defense counsel’s heavy reliance on it during closing argument, reasonable jurors would be compelled to find the care rendered by Dr. Calabrese was appropriate for the condition of diabetes, and, consequently, the trial court’s order denying JNOV is reversed.
IV
Pam argues that the trial court erred in granting summary disposition in favor of defendant on the ground that pam’s failure to have in place a “buy-sell” agreement when notice of Morinelli’s claim was made precluded recovery under the terms of the business buy-out expense disability policy. We disagree.
Pam filed a claim under the business buy-out expense disability policy before defendant terminated payment of benefits to Morinelli under the disability income policy.6 Defendant denied the claim. The policy provided as follows:
*270We will pay benefits to the Loss-Payee for Business BuyOut Expense if: (a) the insured is an owner of the Business and is engaged in Active Full-Tune Work when the Period of Disability starts; and (b) money becomes payable in accordance with the Buy-Sell Agreement because of the Insured’s Total Disability.
The policy defined a buy-sell agreement as “a written agreement between the Business and/or its Principals and the Insured. It must provide for the purchase of the Insured’s ownership interest in the Business due to his/her Total Disability.”
At the time the business buy-out policy was issued, PAM had a shareholder agreement in effect. The agreement stated, in part, as follows:
Upon a Shareholder’s death or termination of employment, the corporation may purchase the shares of its stock held by that Shareholder. If the Corporation purchases less that [sic] all of that Shareholder’s shares, the other Shareholders may purchase the remaining shares. If all of the shares are not purchased, the Corporation shall be dissolved as soon as possible. [Emphasis added.]
According to the application for the buy-out policy, the following question was presented to Morinelli and PAM, which question was answered in the affirmative:
Is it understood that a requirement for the payment of policy benefits is that a written agreement must be in effect between the Business and/or its Principals and the Insured covering the purchase of the Insured’s ownership interest in the Business because of Total Disability of the Insured?
*271It was not until November 1995 that Morinelli and PAM entered into a stock redemption agreement whereby PAM agreed to buy back Morinelli’s stock because of his total disability.7 As such, PAM did not have a buy-sell agreement with regard to Morinelli becoming totally disabled in effect at the time the policy was enacted or when Morinelli filed his claim for disability. The trial court granted defendant’s motion for summary disposition because the buy-sell agreement was created well after either plaintiff had submitted a claim to defendant. Consequently, the trial court did not err in granting summary disposition in favor of defendant with regard to pam’s claim under the buy-out expense disability policy because PAM failed to meet a condition precedent of the insurance policy.
Reversed with regard to the trial court’s denial of Morinelli’s motion for jnov and affirmed with regard to the trial court’s order granting summary disposition of pam’s claim. Remanded for further proceedings consistent with this opinion. We do not retain jurisdiction.
Collins, J., concurred.As an affirmative defense, defendant stated “[t]hat plaintiff Morinelli is not under the care and treatment of a physician, which is appropriate for the conditions of his disability.”
In answer to Morinelli’s interrogatory question, “State each opinion to which the expert is expected to testify and a summary of the grounds for each opinion,” defendant stated as follows:
Dr. [James] Lafleur will testify consistent with his previous statement given to Provident, which is in the possession of the plaintiff, *260as well as his response to plaintiff’s previous lawyer, regarding Mr. Morinelli’s alleged disability. In short, Dr. LaFleur will testify that in his opinion, Mr. Morinelli, notwithstanding his diabetic condition, is perfectly capable of continuing with his profession as a perfusionist, and is therefore not disabled from performing that profession.
In his opening statement, defense counsel emphasized that the word “appropriate” was important, though he did not elaborate.
During the deposition of defense witness Dr. Grunberger, plaintiffs’ counsel asked whether he had any criticism of Dr. Calabrese. Dr. Grunberger answered “no,” although he expressed displeasure with Morinelli’s glycohemoglobin count.
Dr. Calabrese is board certified in the field of internal medicine and has received specialized training in the area of diabetes. Dr. LaFleur, on the other hand, is a family practitioner whose practice includes the treatment of diabetic patients. Had this been a medical malpractice action, Dr. LaFleur would not have been qualified to give standard of care testimony against Dr. Calabrese. MCL 600.2169(l)(a); MSA 27A.2169(l)(a).
As noted by the trial court in its opinion and order granting defendant’s motion for summary disposition:
A thorough review of the Court’s file fails to disclose the exact date that PAM submitted its claim for business buy-out expense benefits payable under the policy, although it appears Plaintiff Morinelli filed his notice of claim under his individual disability policy on October 24, 1994.
*270. . . Therefore, it can reasonably be inferred that pam submitted its claim to Defendant under the provisions of the policy prior to June 23, 1995.
The agreement called for pam to purchase Morinelli’s stock at $900 a share as opposed to the $1 a share price outlined in the shareholder agreement.