dissenting.
The defendant argues the offense of stepchild incest under Neb. Rev. Stat. § 28-703 (Reissue 1995) is unconstitutionally vague and therefore violates the due process provisions of the U.S. Constitution and the Nebraska Constitution, because it prohibits incest with a “minor” stepchild but does not define “minor.” I agree, as does a majority of this court. But the opinion of this court does not decide whether § 28-703 is unconstitutionally vague, based on the court’s conclusion that the statute’s unconstitutionality is not “plainly evident.” Because this issue involves the constitutionality of a statute, the opinion of three judges of this court disposes of the appeal. However, I respectfully disagree with the court’s reasoning, in both the interpretation of the plain error doctrine and the discussion on the constitutionality of § 28-703. Therefore, I respectfully dissent.
PLAIN ERROR
The Court of Appeals found that Johnson’s claim that § 28-703 is unconstitutionally vague had not been properly preserved for *521appellate review in this case, stating that Johnson did not comply with Neb. Ct. R. of Prac. 9E (rev. 2000) because he did not file and serve a separate written notice of the challenge to the statute and because he did not serve a copy of the brief assigning unconstitutionality on the Attorney General. The opinion of the court endorses that conclusion. However, on the same date that Johnson filed his appellate brief, he filed a “Petition to Bypass” with the Supreme Court Clerk’s office, which stated, in relevant part, that “[f]or his appeal, Appellant has alleged that the statute under which he was convicted in [sic] unconstitutionally vague.” Furthermore, rule 9E requires only that the Attorney General be served with a copy of the brief “[i]f the Attorney General is not already a party to an action where the constitutionality of the statute is in issue . ...” In a criminal proceeding, the Attorney General, as the representative of the State of Nebraska, is a party to the proceeding. See Neb. Rev. Stat. § 84-205 (Cum. Supp. 2004). Beyond that, on the last page of Johnson’s appellate brief, his counsel certifies that two copies of the brief were delivered to the Attorney General on the same date that the brief was filed with the Supreme Court Clerk’s office. This suffices, by statute, as proof of service. See Neb. Rev. Stat. § 25-534 (Reissue 1995).
In short, I disagree with the Nebraska Court of Appeals’ conclusion that Johnson failed to follow the requirements of rule 9E and obviously disagree with this court’s endorsement of that conclusion. However, the State also argues that Johnson waived the issue of the constitutionality of § 28-703 because his counsel during pretrial proceedings, who was not his counsel at trial or on appeal, failed to file a motion to quash or a demurrer to either the original or amended information. See State v. Kanarick, 257 Neb. 358, 598 N.W.2d 430 (1999). Because I agree that Johnson should have raised his constitutional claim in a motion to quash, I also agree that consideration of that constitutional claim requires the court to find plain error.
But because Johnson’s conviction was based on § 28-703 and because this appeal cannot be resolved without interpretation of § 28-703, the constitutionality of § 28-703 should be considered despite Johnson’s procedural failures. This court has stated that “where the invalidity of the act is plain, and such a determination is necessary to a reasonable and sensible disposition of the issues *522presented, we are required by necessity to notice the plain error in the premise on which the case was tried.” State v. Goodseal, 186 Neb. 359, 368, 183 N.W.2d 258, 263-64 (1971). Because the assignments of error in this appeal require interpretation of § 28-703, the court cannot reach a sound and reasonable disposition of this appeal without confronting the constitutionality of the stepchild incest statute — i.e., whether the meaning of § 28-703 can be reasonably determined.
In other words, the court cannot resolve the arguments Johnson has preserved for appellate review without, at least implicitly, resolving those that he arguably did not. The court should not permit the mistakes of counsel to force it into making a determination that inevitably results from attempting to discern the meaning of statutory language that defies meaningful definition. In my opinion, the court’s “interpretation” of § 28-703 does what the Due Process Clause was intended to prevent — it retroactively purports to give validity to a statute that, without the court’s interpretation, is effectively meaningless.
The court avoids discussing the due process issue by stating that “the issues in this appeal can be resolved without addressing the constitutionality of § 28-703.” (Emphasis supplied.) This is true, but the question is whether the issues should be resolved without addressing the constitutionality issue. The problem is that the resolution of the issues in this appeal implicates the constitutionality of § 28-703, regardless of whether it is openly addressed. It is simply not possible to construe a statute yet avoid determining whether the statute is capable of meaningful construction in the first instance. That the court includes a significant amount of discussion regarding the vagueness of § 28-703 provides some indication of how much the constitutional issue is a necessary concomitant to the other issues presented in this appeal.
The opinion of the court further concludes that the plain error doctrine is not satisfied in this case because the error is not “plainly evident from the record.” See State v. Mata, 266 Neb. 668, 699, 668 N.W.2d 448, 477 (2003), cert. denied 543 U.S. 1128, 125 S. Ct. 1088, 160 L. Ed. 2d 1081 (2005). For reasons I will explain below, I respectfully disagree. But my initial dispute with the court’s reasoning is that it is mistaken to invoke that proposition at all, because the constitutional issue the court is called *523upon to decide is a necessary and intrinsic part of its analysis of § 28-703, regardless of whether the error is plainly evident from the record. See State v. Goodseal, supra. “The Nebraska Supreme Court will not pass upon the constitutionality of legislation absent a need to do so in order to properly dispose of an action.” (Emphasis supplied.) State v. VanAckeren, 263 Neb. 222, 229-30, 639 N.W.2d 112, 118 (2002). Consideration of plain error occurs at the discretion of an appellate court. State v. Al-Zubaidy, 257 Neb. 935, 602 N.W.2d 8 (1999). In my opinion, the court should exercise that discretion under these circumstances.
Beyond that, however, the court has conflated the plainness of error, and the degree of prejudice sustained by the defendant, with the difficulty of the legal question presented. Plain error is error plainly evident from the record and of such a nature that to leave it uncorrected would result in damage to the integrity, reputation, or fairness of the judicial process. State v. Bartholomew, 258 Neb. 174, 602 N.W.2d 510 (1999). The court concludes that the error in this case was not “plainly evident” because statutes are presumably constitutional, and there is a rational argument supporting the constitutionality of § 28-703. The court seems to be saying that for error to be plain, it must be indisputable. But the foregoing standard for plain error does not say that. Instead, it refers to error “plainly evident from the record.” (Emphasis supplied.) See State v. Bartholomew, 258 Neb. at 180, 602 N.W.2d at 514. In other words, the record must plainly demonstrate that the error occurred. It is not required that the legal issue before the court be an easy one to decide. Whether error is plainly evident cannot be dependent on the mental exertion necessary for a judge to decide the issue.
. The constitutionality of a statute is a question of law, and the Supreme Court is obligated to reach a conclusion independent of the decision reached by the trial court. State v. Diaz, 266 Neb. 966, 670 N.W.2d 794 (2003). While I agree that Johnson should have raised his constitutional claim with a timely motion to quash, see State v. Kanarick, 257 Neb. 358, 598 N.W.2d 430 (1999), it is worth noting that Johnson did make his constitutional argument, albeit belatedly, in the trial court and that the trial court ruled on his motion. We have said that generally, a constitutional issue not presented to or passed upon by the trial court is not appropriate for consideration on appeal. See State v. Diaz, supra. While *524Johnson’s motion was untimely, he nonetheless made a record of his constitutional objection in the trial court, the parties were heard on the matter, and the trial court ruled on the objection. Moreover, whether a statute is unconstitutionally vague is determined from the language of the statute, which is obviously available to this court.
When a vagueness argument under the Due Process Clause is raised, the constitutionality or unconstitutionality of the statute is plainly evident one way or the other. Either a statute is unconstitutional or it is not — there is no middle ground. Whether § 28-703 is unconstitutional is a straightforward question of law that is as “plainly evident” in this case as it would be in any other.
VOID-FOR-VAGUENESS DOCTRINE
The void-for-vagueness doctrine bars enforcement of a statute which either forbids or requires the doing of an act in terms so vague that persons of common intelligence must necessarily guess at its meaning and differ as to its applications. State v. Caddy, 262 Neb. 38, 628 N.W.2d 251 (2001), citing United States v. Lanier, 520 U.S. 259, 117 S. Ct. 1219, 137 L. Ed. 2d 432 (1997). A statute is vague if its prohibitions are not clearly defined. State v. Frey, 218 Neb. 558, 357 N.W.2d 216 (1984).
Due process of law requires that criminal statutes be clear and definite. State v. Pierson, 239 Neb. 350, 476 N.W.2d 544 (1991). A crime must be defined with sufficient definiteness and there must be ascertainable standards of guilt to inform those subject to the statute as to what conduct will render them liable to punishment, and the dividing line between what is lawful and unlawful cannot be left to conjecture. Id. A crime and its elements must be so clearly expressed that an ordinary person can intelligently choose in advance what course of conduct he or she may lawfully pursue. Robotham v. State, 241 Neb. 379, 488 N.W.2d 533 (1992).
The void-for-vagueness doctrine requires that a penal statute define the criminal offense with sufficient definiteness that ordinary people can understand what conduct is prohibited. State v. Faber, 264 Neb. 198, 647 N.W.2d 67 (2002). Because § 28-703 does not define “minor,” it does not define the crime of incest with a stepchild with sufficient definiteness that ordinary people can be certain what conduct is prohibited. As Johnson notes, Nebraska *525statutes, including criminal statutes, give varying definitions of when a person is a “minor.” The Court of Appeals recognized that
[t]he age of majority is set at different ages for different purposes. See, e.g., Neb. Rev. Stat. § 25-508.01 (Reissue 1995) (for purposes of personal service, minor is person under 14 years of age); Neb. Rev. Stat. § 28-443 (Reissue 1995) (in regard to prohibition of delivery of drug paraphernalia to minor, minor is person under 18 years of age who is at least 3 years younger than actor); Neb. Rev. Stat. § 28-805 (Reissue 1995) (debauching minor prohibits non-minor from debauching morals of boy or girl under age of 17); Neb. Rev. Stat. § 28-1418 (Reissue 1995) (prohibiting use of tobacco by minor under age of 18); Neb. Rev. Stat. § 53-103(23) (Cum. Supp. 2002) (for purposes of Nebraska Liquor Control Act, minor means any person under 21 years of age, regardless of marital status).
State v. Johnson, 12 Neb. App. 247, 257-58, 670 N.W.2d 802, 812 (2003). Despite this multitude of definitions, the Court of Appeals concluded that Neb. Rev. Stat. § 43-2101 (Reissue 2004), which defines “minor” generally as a person under 19 years of age, defined “minor” for purposes of § 28-703. The opinion of the court endorses that conclusion, although that conclusion does not command a majority of this court.
Because of the varying definitions of “minor” in Nebraska statutes, I do not believe that the use of the word “minor” in § 28-703 was sufficiently definite to give the ordinary person notice of whether sexual conduct involving a stepchild between the ages of 16 and 19 was prohibited. Although the Court of Appeals and the opinion of the court have articulated plausible reasons to choose the definition provided in § 43-2101, there is nothing in § 28-703 or elsewhere that would alert the ordinary person that such was the definition of “minor” for purposes of § 28-703. Indeed, the Court of Appeals and the opinion of the court could have used the definition from one of the criminal statutes, such as Neb. Rev. Stat. § 28-805 (Reissue 1995) (debauching or depraving morals of minor, defined as under age 17) or Neb. Rev. Stat. § 28-319(1) (Reissue 1995) (criminalizing adult’s sexual conduct when actor is age 19 or older and victim is under age of 16), and stated reasons for such a selection that would have been just as persuasive *526as the reasons they have given for selecting the definition from § 43-2101.
The Court of Appeals relied, in interpreting § 28-703, upon the familiar proposition that in reading a statute, a court must determine and give effect to the purpose and intent of the Legislature as ascertained from the entire language of the statute considered in its plain, ordinary, and popular sense. See State v. Aguilar, 268 Neb. 411, 683 N.W.2d 349 (2004). However, the issue in this appeal is not what the Legislature may have intended to do — rather, the issue is whether the Legislature’s intent, whatever it may have been, was successfully translated into a statute that effectively defined the line between lawful and unlawful conduct.
But beyond that, other familiar maxims of statutory interpretation support contrary conclusions. The Court of Appeals cited the proposition that
“ ‘ “[an appellate court], in construing a statute, looks to the objects to be accomplished, the evils and mischief sought to be remedied, or the purposes to be served, and places upon the statute a reasonable or liberal construction which will best effect its purpose rather than one which will defeat it..
(Emphasis supplied.) State v. Johnson, 12 Neb. App. at 258, 670 N.W.2d at 812-13. Accord, e.g., Mathews v. Mathews, 267 Neb. 604, 676 N.W.2d 42 (2004). But it is also a fundamental principle of statutory construction that penal statutes are to be strictly construed in favor of the defendant, and it is well understood that it is not for the courts to supply missing words or sentences to make clear that which is indefinite, or to supply that which is not there. See, State v. Hochstein and Anderson, 262 Neb. 311, 632 N.W.2d 273 (2001); State v. Jansen, 241 Neb. 196, 486 N.W.2d 913 (1992). Simply stated, § 28-703 is meaningless unless a definition of the word “minor” is imported from another statute, and our familiar maxims of statutory interpretation are of little assistance in determining which definition, if any, is to be applied. But more to the point, § 28-703 provides nothing that would suffice to inform the ordinary citizen which definition was applicable.
I recognize that difficulty in determining the meaning of the language of a statute does not automatically render it unconstitutionally vague and ambiguous. See State v. Sodders, 208 Neb. *527504, 304 N.W.2d 62 (1981). But when a court could reasonably give conflicting definitions to a term used in a penal statute, the statute does not give an ordinary citizen adequate notice of prohibited conduct because the citizen cannot know which definition the court will choose. While this court could authoritatively articulate a meaning for § 28-703, that determination could not be applied retroactively, as the opinion of the court would hold, unless such application provided fair warning to the defendant. See State v. Ehlers, 252 Conn. 579, 750 A.2d 1079 (2000), citing Dombrowski v. Pfister, 380 U.S. 479, 85 S. Ct. 1116, 14 L. Ed. 2d 22 (1965). All crimes in Nebraska are statutory in nature, State v. White, 256 Neb. 536, 590 N.W.2d 863 (1999), and Nebraska’s statutory scheme has not provided fair warning to the defendant of what conduct is prohibited under § 28-703.
I am aware, as noted by the opinion of the court, that courts in other jurisdictions have concluded that the failure to define the word “minor,” under the respective statutory schemes presented in those cases, did not render those statutes unconstitutionally vague. See, State v. Duggar, 806 S.W.2d 407 (Mo. 1991) (en banc); State v. Young, 37 Ohio. St. 3d 249, 525 N.E.2d 1363 (1988), reversed in part on other grounds sub nom. Osborne v. Ohio, 495 U.S. 103, 110 S. Ct. 1691, 109 L. Ed. 2d 98 (1990); State v. Jackson, 280 N.C. 563, 187 S.E.2d 27 (1972); People v. Vassar, 207 Cal. App. 2d 318, 24 Cal. Rptr. 481 (1962). However, those conclusions are not persuasive in the instant case.
In each of those cases, the court found that the term “minor” could be defined by reference either to the common law, as in Duggar and Jackson, or to a civil statute that the court determined to be of general application, as in Young and Vassar. While that reasoning may have merit, it is not applicable to the circumstances of this case. As previously noted, the Nebraska statutes contain several provisions that define the term “minor” for specific purposes. While the court argues, as did the Court of Appeals, that § 43-2101 provides an applicable definition, I am not persuaded, for the reasons previously explained, that the ordinary citizen would have had sufficient reason to expect that definition, as opposed to any other, to be lifted from another chapter of the Nebraska Revised Statutes and used to provide clarity to an otherwise indefinite penal statute.
*528Because we assume that people are free to steer between lawful and unlawful conduct, we insist that laws give people of ordinary intelligence a reasonable opportunity to know what is prohibited, so that they may act accordingly. See State v. Frey, 218 Neb. 558, 357 N.W.2d 216 (1984), citing Grayned v. City of Rockford, 408 U.S. 104, 92 S. Ct. 2294, 33 L. Ed. 2d 222 (1972). Section 28-703, however, contains no definition for a critical term and provides no indication what definition, if any, is to be applicable. It does not meet the requirements of due process and is unconstitutionally vague. Johnson’s conviction, pursuant to an unconstitutionally vague statute, was plain error.
CONCLUSION
I would conclude that the portion of § 28-703 dealing with conduct involving a minor stepchild is unconstitutionally vague because it does not define “minor” and that this error is plainly evident from the record. Consequently, I would reverse the judgment of the Court of Appeals and remand the cause with directions to reverse Johnson’s conviction and sentence. Having determined that § 28-703 is unconstitutional, I would not reach Johnson’s remaining assignments of error.
Wright, Connolly, and McCormack, JJ., join in this dissent.