Definition
Sanguinity, in legal contexts, refers to the relationship of blood; consanguinity or kinship by descent from a common ancestor. The term appears in older property and inheritance law as a shorthand for blood relationship, particularly in distinguishing heirs of the blood from those connected by marriage or adoption. It is closely associated with — and often used interchangeably with — consanguinity in historical legal writing.
Note on the Bouvier entry: The historical dictionary entry supplied under this heading appears to describe a different term (likely "severance" or a boundary-related concept in real property), and does not reflect the actual legal usage of sanguinity. Researchers should treat that entry as a misattribution or indexing error in the source material. The definition above reflects the term's actual legal meaning as it appears in the broader common law tradition.
---
Common Language
Modern common usage (Wiktionary): The quality of being sanguine; sanguineness — i.e., optimism or cheerfulness.
Historical common usage (Webster's 1913): The quality of being sanguine; sanguineness.
The gap here is significant. In ordinary English, sanguinity derives from the figurative sense of "sanguine" meaning hopeful or confident in temperament — a meaning rooted in the humoral theory that an abundance of blood produced a cheerful disposition. In legal usage, the term returns to the literal root: sanguis (Latin for blood), meaning kinship through blood descent. A researcher encountering sanguinity in a legal instrument, will, or inheritance dispute should read it as a relationship term, not a temperamental one.
---
Why It Matters in Research
Sanguinity is a low-frequency term that surfaces mainly in older wills, intestacy proceedings, and real property instruments where heirs "of the blood" are distinguished from spouses or strangers to the blood. Because the word is rare in formal legal taxonomy — consanguinity being the far more common form — it can be missed in keyword searches that do not account for variant spellings and shortened forms.
Researchers working in colonial American, early English, or civil law-influenced jurisdictions (particularly Louisiana) should be alert to this term appearing alongside half-blood distinctions, where the degree of sanguinity determined inheritance rights. In those contexts, sanguinity is not decorative language — it is a term of art that controls which heirs take and in what proportion.
The misattributed Bouvier entry (describing real property boundaries) is a practical trap: a researcher relying on that dictionary entry alone would have no useful guidance on the term's actual legal function. Cross-referencing with consanguinity entries in Bouvier and Black's will supply the missing framework.
---
Historical Dictionary Support
Bouvier's Law Dictionary, as supplied, does not offer a usable entry for sanguinity in its legal sense. The entry provided describes boundary concepts in real property — almost certainly a different headword entry that has been misassigned. This is not unusual in digitized or indexed versions of historical dictionaries, where proximity in alphabetical arrangement can produce indexing errors.
Black's Law Dictionary (not supplied but part of the standard shelf) defines consanguinity with precision and treats sanguinity as a variant form. Older English legal dictionaries in the common law tradition, including Termes de la Ley and Cowell's Interpreter, use sanguinity and consanguinity interchangeably when discussing the rules of inheritance and the canonical degrees of relationship that determined both succession rights and the law of marriage impediments.
What historical sources collectively miss: none of the major historical dictionaries treat sanguinity as a standalone term with independent legal content. Its legal life is entirely derivative of consanguinity, and researchers should pursue that headword for full doctrinal treatment.
---
Jurisdictional Note
In American jurisdictions, sanguinity as a discrete term is largely obsolete in modern statutes, which use consanguinity or simply "blood relative." In civil law jurisdictions and in ecclesiastical law (which historically governed marriage impediments), degrees of sanguinity carried precise computational meaning that differed between the Roman and canonical methods of counting. Researchers in Louisiana law or in historical canon law contexts should be attentive to which counting method the source document employs.
---