Definition
A Latin term from the civil law meaning "sister." In legal contexts, *soror* appears primarily as a building block in civil law texts and glossaries concerned with family relationships, consanguinity, and intestate succession. It is not an operative term of art in modern Anglo-American law but surfaces in historical legal materials — particularly in discussions of degrees of kinship derived from Roman law — where the Latin terminology was preserved long after vernacular equivalents became standard.
Common Language
Modern common usage (Wiktionary): A sorority sister; a fellow member of one's sorority.
Historical common usage (Webster's 1913): No entry; the word had not entered general English usage by that date.
The modern colloquial use of *soror* is entirely distinct from its civil law function. The legal term is a Latin noun denoting a biological or legally recognized sister in the context of kinship and inheritance. The sorority usage is a 20th-century American coinage derived from the same Latin root but carrying no legal weight.
Common Confusion
The Second Edition of Black's Law Dictionary includes a fragmentary and garbled note referencing "sororicide" — the killing of a sister — and correctly observes that this is not a technical term of the law. Researchers should not treat *sororicide* as a legal term of art encountered in primary sources; it is a descriptive Latin compound occasionally used in commentary, not in pleading or statute.
Why It Matters in Research
*Soror* is encountered almost exclusively in two contexts within the Law Mind corpus: (1) civil law treatises and institutional texts citing Roman sources, particularly the Institutes of Justinian (Inst. 3, 6, 1), where the term appears in tables of consanguinity governing intestate succession; and (2) legal glossaries and Latin law dictionaries that preserved Roman terminology for practitioners trained in the ius commune tradition.
Researchers working in early American or colonial legal materials, ecclesiastical law, or Louisiana civil law sources are most likely to encounter the term. In common law jurisdictions, the equivalent concept was rendered in English or Norman French, so *soror* rarely appears in case law or statutes outside of quoted Latin maxims.
The principal research trap is over-reading the term as a standalone legal concept. *Soror* functions as a relational descriptor within a larger system of consanguinity classification — it has meaning only in relation to *frater* (brother), *pater* (father), *mater* (mother), and the broader degree structure. Encountering it in isolation, without the surrounding kinship table or succession analysis, can mislead a researcher into thinking it carries independent legal significance.
The garbled text in the Second Edition of Black's entry — likely a typesetting artifact from early printing — should be treated with caution. The reference to "masts 3, 6, 1" is a corruption of "Inst. 3, 6, 1," the standard citation to Justinian's Institutes. Burrill's entry similarly shows corruption ("self from obligation, as by payment of a la sister"), reflecting transcription or printing errors that are common in digitized versions of 19th-century dictionaries. Neither corruption alters the substance of the definition.
Historical Dictionary Support
All three source dictionaries agree on the core definition: *soror* is Latin for "sister" as used in the civil law, with the authoritative citation being Justinian's Institutes, Book 3, Title 6. There is no substantive disagreement among the sources on meaning.
Burrill adds a citation to Calvin's *Lexicon Juridicum* (*Calv. Lex.*), a standard Renaissance-era Latin legal dictionary, which confirms the term's place in the ius commune scholarly tradition rather than in English common law practice. This distinguishes *soror* from terms that crossed into English legal usage; it remained a Latinate reference point, not an assimilated term of art.
The Second Edition of Black's attempted to note the related compound *sororicide* but did so in a corrupted passage. The underlying point — that the killing of a sister has no distinct legal name in Anglo-American law — is accurate and worth preserving for researchers who encounter the compound in Latin legal commentary.
What historical dictionaries do not address is how *soror* functioned within the computational tables of consanguinity used in ecclesiastical courts to adjudicate marriage impediments and in civil courts to determine heirship. For that context, researchers must go beyond the dictionary entry to treatises on succession and canon law.