Definition
Cousinage is an archaic legal term referring to the relationship of cousinhood or kinship — that is, the state of being related by blood through a common ancestor. In medieval common law, it had specific procedural significance as the name of a real action: the writ of cousinage (also spelled cosinage) was a remedy available to a claimant who had been disseised of lands to which he claimed title through a great-grandparent's collateral line. All three source dictionaries treat COUSINAGE as a direct cross-reference to COSINAGE, where the substantive legal content is located. See COSINAGE for full treatment.
Common Language
Modern common usage (Wiktionary): relationship; kinship.
Historical common usage (Webster's 1913): "Relationship; kinship." Marked as obsolete, with attribution to Wyclif.
Both the common and legal meanings share the same root sense of kinship, but the legal term carried a precise technical function that the ordinary word never had. In common speech, cousinage was simply a vague descriptor of family connection. In the common law of real actions, it named a specific writ tied to a defined degree of consanguinity and a particular chain of descent — a procedural tool, not merely a relational description. A researcher encountering the term in a common-language source should not assume it conveys that technical meaning.
Common Confusion
COUSINAGE and COSINAGE are spelling variants of the same term, and the source dictionaries use both interchangeably, with COUSINAGE serving as the secondary form. Neither should be confused with NUPER OBIIT or MORT D'ANCESTOR, which were related but distinct real actions addressing different degrees of kinship and different triggering events. Researchers should also note that "cousin" in medieval legal usage frequently meant any collateral relative, not merely the modern sense of a first cousin — a distinction that matters when reading older writ pleadings.
Why It Matters in Research
COUSINAGE functions almost entirely as a pointer term in the historical dictionaries. Its value to a researcher lies in recognizing it as a variant spelling of COSINAGE and following that cross-reference rather than treating the entry as self-contained. Researchers working in medieval land law sources, plea rolls, or abridgments may encounter either spelling depending on the period and the scribe; standardization was inconsistent through the early modern period.
The term appears in sources dealing with the old real actions, a body of procedure largely abolished in England by the Real Property Limitation Act 1833 and displaced in American practice much earlier, if it took root at all. Researchers using American sources post-Revolution will rarely encounter cousinage as a live procedural term; when it appears, it is almost always in a historical or comparative context.
The common-law real actions as a family — cousinage, nuper obiit, mort d'ancestor, novel disseisin — form an interconnected web in the historical sources. Understanding cousinage requires understanding where it sat in the hierarchy of these writs, which is covered under COSINAGE.
Historical Dictionary Support
All three dictionaries — Black's, Bouvier's, and Burrill's — treat COUSINAGE identically: a bare cross-reference to COSINAGE with no independent analysis. This unanimity is itself informative. The term was recognized as part of the legal vocabulary but received no standalone treatment because its content lived entirely under the variant spelling. Bouvier's entry for COUSINAGE shares its page with COUSTUM and COUSTUMIER, placing the term in the context of Norman-derived legal vocabulary, which reflects the French-origin lineage of cousinage (from the Old French cosin or cousin) and its transmission into English common law through the Norman legal tradition. None of the dictionaries offer case references or statutory citations for cousinage specifically.