Definition
Lasciviousness is a legal term of art denoting conduct, expression, or material that tends to excite sexual desire or that reflects a wanton disregard of sexual propriety. In criminal law and regulatory contexts, it describes a quality of indecency oriented toward sexual impurity — not mere nudity or vulgarity, but something that appeals to or arouses prurient interest.
The term appears most frequently in three overlapping legal contexts:
1. Criminal statutes prohibiting lascivious acts, speech, or exhibition — particularly as applied to conduct involving minors, public indecency, or obscene communications.
2. Federal law governing the mailing or transportation of obscene materials, where "lascivious" has historically been used alongside "lewd," "indecent," and "filthy" as terms describing prohibited content.
3. Civil and administrative proceedings involving the fitness of individuals or the licensing of establishments, where lascivious conduct may constitute grounds for disqualification, revocation, or restriction.
Lasciviousness does not require proof of a completed sexual act. The term captures the quality or character of conduct rather than its outcome.
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Common Language
Modern common usage (Wiktionary): "The characteristic or state of being lascivious" — that is, being driven by or expressing lustful desire.
Historical common usage (Webster's 1913): Wanton; lewd; lustful; tending to produce voluptuous or lewd emotions.
The common meaning and the legal meaning overlap substantially in tone, but diverge in application. In ordinary usage, lasciviousness describes a personal moral quality — a disposition of the mind or character. In law, it functions as an objective descriptor of conduct or material assessed by an external standard: whether the thing in question would excite sexual desire in an ordinary observer, or whether it falls within the class of expression that a jurisdiction has determined to be sexually impure. The legal question is not what the actor felt, but what the conduct or material communicates.
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Common Confusion
Lasciviousness, lewdness, and obscenity are frequently treated as interchangeable in both statutes and legal opinions, but they are not technically synonymous.
Obscenity is the broadest and most constitutionally defined category, governed in the United States by the three-part test articulated in Miller v. California (1973). Lewdness typically refers to outward, observable conduct of a sexually indecent character. Lasciviousness emphasizes the tendency to arouse or excite — a quality directed at the effect on an audience or the character of the material itself, rather than the nature of the act alone.
In practice, many statutes list these terms together rather than parsing them. Researchers should not assume that a court treating them as synonymous has resolved their technical distinctions; it may simply have found the distinction unnecessary to the holding.
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Why It Matters in Research
Several research traps attend this term.
First, lasciviousness is a term whose legal content has been substantially shaped by constitutional developments that postdate the historical dictionaries. Bouvier's entries reflect a Victorian-era moral framework in which the standard for lasciviousness was essentially community moral consensus, without formal doctrinal scaffolding. That framework was displaced — or at least constrained — by First Amendment jurisprudence over the twentieth century. A researcher relying on Bouvier's definition without consulting modern doctrine risks applying a standard that courts have since qualified or narrowed.
Second, the term's meaning in federal criminal statutes governing minors (particularly provisions addressing "lascivious exhibition" of minors' genitalia) has been the subject of sustained circuit court interpretation. The term does real definitional work in those contexts, and its meaning has been calibrated by case law rather than statutory definition. Historical dictionary entries will not supply that calibration.
Third, because statutes routinely string together lewdness, lasciviousness, indecency, and obscenity, corpus researchers should run searches for all four terms when investigating a statutory scheme or a body of common law. The presence of one term in an opinion does not mean the others are absent from the governing standard.
Fourth, researchers working in historical materials — particularly nineteenth and early twentieth century federal cases involving the mails — will encounter lasciviousness as a live term of art with significant prosecutorial history. In that corpus, the term carries genuine doctrinal weight and should not be read as mere moralizing rhetoric.
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Historical Dictionary Support
Bouvier's treats lasciviousness and lewdness as "generally interchangeable if not synonymous terms," and grounds the definition in sexual impurity as a form of immorality. The entry cites federal circuit authority (51 Fed. Rep. 41) for the proposition that lasciviousness has reference to sexual impurity generally, confirming the term's active use in federal courts by the late nineteenth century.
Bouvier's observation that both terms are used primarily "in a secondary or derived meaning" is notable. The primary meanings of both words were descriptive of personal moral character; the legal uses were derivative applications of that moral vocabulary to conduct and expression subject to public regulation. This genealogy helps explain why the terms resist precise definition: they were borrowed from moral discourse and never fully translated into technical legal categories with bright-line content. Courts have long acknowledged this imprecision while continuing to apply the terms.
What Bouvier's does not address — because it could not — is the subsequent constitutional overlay. The framework within which lasciviousness now operates in American law is filtered through First Amendment doctrine, and historical dictionary entries should be used only for period-accurate research, not as statements of current operative law.
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Jurisdictional Note
Lasciviousness appears in both federal and state criminal codes, but its operative meaning varies by context. Federal statutes addressing child exploitation have generated the most developed body of interpretive case law. State statutes governing public indecency and obscenity use the term with varying definitional precision, and some states have moved toward more specific conduct-based language in modern revisions.
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Encyclopedia Cross-Reference
Law Mind Encyclopedia — Obscenity and Indecency
Law Mind Encyclopedia — Sexual Offenses
Law Mind Encyclopedia — First Amendment and Expressive Conduct
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