Definition
Sexual contact between a human being and an animal. As a criminal offense, bestiality is treated in most American and common law jurisdictions as a felony or serious misdemeanor, variously classified under statutes prohibiting crimes against nature, sodomy, animal cruelty, or a dedicated bestiality prohibition depending on the jurisdiction and era of the statute.
The term carries a precise legal referent: the act itself, without regard to the sex of the human participant. Historically, legal definitions emphasized "carnal knowledge against the order of nature" as the organizing concept, linking bestiality closely to sodomy under the broader common law category of crimes against nature.
Common Language
Modern common usage (Wiktionary): Sexual activity between a human and another animal species; also, secondarily, bestial nature, savagery, or animal-like instinct or behavior.
Historical common usage (Webster's 1913): "The state or quality of being bestial. Unnatural connection with a beast."
Editorial note: The common and legal meanings overlap substantially here. The legal term, however, is narrower than everyday usage of "bestial" or "bestiality" in the sense of brutishness or savagery — usage courts occasionally encountered when interpreting statutes. The moral-descriptive register of the word (inhuman, savage) has no legal operative significance; only the specific sexual act triggers criminal liability.
Common Confusion
Bestiality and sodomy are closely related but distinct terms in legal history, and the historical sources frequently blur the boundary. Sodomy, at common law, referred to anal intercourse between humans (male-male in the classic formulation) or between a human and an animal. Bestiality was understood by some authorities as the species-crossing act specifically, separate from the human-to-human variant of sodomy. Bouvier notes that "buggery seems to include both sodomy and bestiality," and Black's 2nd Edition makes an explicit effort to distinguish the terms. Anderson simply cross-references sodomy without drawing the distinction. In practice, statutes historically grouped these acts under a single "crimes against nature" heading, making the definitional line legally immaterial in many prosecutions. Researchers should not assume that a historical source using "sodomy" excludes bestiality, or vice versa.
Why It Matters in Research
Statutory location has shifted substantially across time and jurisdiction. Before the mid-twentieth century, bestiality prosecutions in American courts almost always proceeded under general "crimes against nature" or "sodomy" statutes. A researcher looking for bestiality case law in nineteenth or early twentieth century reporters should search under those headings, not under "bestiality" as a standalone charge.
Following Lawrence v. Texas (2003), which invalidated sodomy laws as applied to consensual adult human conduct, many states undertook statutory revision. In that process, some jurisdictions separated bestiality from sodomy statutes entirely and enacted standalone animal sexual abuse laws, often situated in animal cruelty codes rather than sex offense codes. Others retained omnibus language. This creates a classification inconsistency across secondary sources: a modern encyclopedia may list bestiality under animal cruelty while a nineteenth-century digest lists the same conduct under crimes against nature or unnatural offenses.
Animal cruelty framing has also introduced a secondary victim analysis in modern statutes — the animal as victim rather than the act as offense against God or natural order — which carries sentencing, registration, and civil consequences that older sources do not reflect.
Researchers working on sentencing, sex offender registration, or civil commitment questions should verify whether the jurisdiction's bestiality statute is coded as a sex offense, an animal cruelty offense, or both, as registration and commitment consequences may turn on that classification.
Historical Dictionary Support
The four source dictionaries show a consistent but compressed treatment. Black's 1st Edition and 2nd Edition both define the act as "carnal knowledge and connection against the order of nature by man or woman in any manner with a beast," with the 2nd Edition attempting to draw a formal distinction between bestiality and the broader crime against nature. That distinction — that bestiality specifically involves a human and a brute of the "opposite sex" — appears in both Black's 2nd and Bouvier and reflects a now-obsolete interpretive constraint. Modern statutes do not incorporate an opposite-sex requirement, and no contemporary jurisdiction is known to limit criminal liability on that basis.
Bouvier's brief note that buggery encompasses both sodomy and bestiality reflects English common law inheritance, where the ecclesiastical and then secular courts treated all three as varieties of the same genus. Anderson's bare cross-reference to sodomy is consistent with the historical legal practice of subsuming bestiality within that broader category.
None of the historical dictionaries address animal cruelty dimensions, registration consequences, or the post-Lawrence statutory landscape — all of which now define how the term functions in active legal research.
Jurisdictional Note
As of the early twenty-first century, most U.S. states criminalize bestiality, but the statutory basis, severity, and sex offender registration consequences vary significantly. Some states classify it as a felony sex offense triggering registration; others treat it primarily as a misdemeanor animal cruelty violation with no registration requirement. A small number of states have, at various points, lacked an explicit prohibition and have had to rely on general animal cruelty or crimes against nature statutes. Researchers must verify current statutory classification in the relevant jurisdiction before drawing conclusions about consequences.