Definition
In law, "uncle" designates the brother of one's father or mother. The term identifies a specific degree of collateral consanguinity and appears most frequently in contexts that turn on family relationship: intestate succession, prohibited degrees of marriage, disqualification rules, and occasionally criminal statutes addressing sexual offenses or incest. The uncle relationship is collateral (not lineal) and stands two degrees removed from a common ancestor in most civil-law counting systems, or three degrees removed under the common-law canonical method.
Common Language
Modern common usage (Wiktionary): A cry used to indicate surrender; also, the brother of one's father or mother, or the husband of one's aunt.
Historical common usage (Webster's 1913): The brother of one's father or mother; also applied to an aunt's husband. Colloquially, a pawnbroker (slang, as in Thackeray). Also: "Uncle Sam," a humorous name for the United States Government.
The legal definition is narrower than common usage in one important respect: law generally limits "uncle" to a blood relation — the brother of a parent — and does not extend it to an aunt's husband unless a statute expressly says so. When a will, intestacy statute, or marriage-prohibition provision uses the word "uncle," researchers should not assume the marital extension applies without checking the governing instrument or code.
Core Elements
Two elements define the legal uncle relationship:
1. A common ancestor: the uncle and the subject share at least one grandparent.
2. Generational offset: the uncle is one generation above the subject in the collateral line — he is the sibling of a parent, not a sibling of the subject.
Half-uncles (where the uncle and the parent share only one common grandparent) may or may not be treated identically to full uncles depending on the jurisdiction and the legal context. Researchers should verify whether a given statute or instrument addresses half-blood relationships explicitly.
Why It Matters in Research
The practical legal significance of "uncle" almost always arises in one of three contexts:
Intestate succession: Most intestacy schemes reach uncles only after closer relatives are exhausted. The precise degree at which uncles inherit — and whether they are grouped with aunts and first cousins or treated as a distinct class — varies by jurisdiction and era. Nineteenth-century statutes often used Roman-derived degree-counting (civil law method), while English-influenced codes used canonical counting. The same word "uncle" can represent a different degree number depending on which system the drafting legislature adopted, which affects priority among heirs.
Prohibited marriages and incest statutes: Many states prohibit marriage between a niece and her uncle, and criminal incest statutes frequently list the uncle-niece pair explicitly. Whether "uncle" in these provisions includes half-uncles, step-uncles, or adoptive uncles is a recurring interpretive question. Historical sources almost uniformly address only blood uncles; modern statutes vary significantly.
Witness disqualification and conflict rules: Older procedural rules disqualified witnesses related within certain degrees. An uncle fell within the prohibited range under most formulations, but the degree-counting method again determined the outcome. Researchers working with pre-twentieth-century transcripts or reported decisions should be alert to which counting method the court applied.
One practical trap: Anderson's entry simply redirects to CONSANGUINITY without defining the term independently. Researchers relying on Anderson alone will not find a standalone definition; they must follow the cross-reference.
Historical Dictionary Support
The historical sources are consistent and minimal. Black's (both editions), Bouvier, and Anderson agree that an uncle is the brother of a father or mother — nothing more. Black's second edition adds two case citations (State v. Reedy, Kansas, 1890; State v. Guiton, Louisiana, 1899), both arising in criminal contexts, suggesting the primary litigation driver in the period was incest or sexual offense statutes rather than inheritance disputes.
Bouvier adds the Latin cross-references AVUNCULUS (mother's brother) and PATRUUS (father's brother), preserving a Roman-law distinction that English common law largely collapsed. This distinction matters for researchers working with civil-law jurisdictions (Louisiana, Quebec-influenced materials) or with early American sources drawing on civilian tradition: a maternal uncle and a paternal uncle were legally distinguishable concepts in Roman and early civil law, and some early American courts or treatise writers preserved the distinction.
What the historical dictionaries do not address: adoption, step-relationships, half-blood, and the marital extension (aunt's husband). These gaps are significant for modern research but were not live questions when the entries were written.
Jurisdictional Note
Louisiana's civil-law heritage means its degree-of-relationship counting has historically followed the civil-law method, which may produce different numerical results from common-law canonical counting even when the underlying family facts are identical. Researchers working across Louisiana and common-law state sources should confirm which method applies before relying on degree numbers from one system in the other.