Definition
A Roman civil law term designating a great-aunt — specifically, the sister of one's grandmother (on either side). The term is the feminine counterpart of patruus magnus (great-uncle) and belongs to the precise system of kinship nomenclature developed under Roman law to identify degrees of consanguinity for purposes of inheritance, intestate succession, and the rules governing who could serve as guardian or heir.
In civil law systems derived from Roman sources, exact kinship terminology carried legal weight because inheritance rights and the order of succession depended on calculating the precise degree of relationship between the decedent and potential heirs. Matertera magna occupies a defined position in that calculus.
Why It Matters in Research
This term appears almost exclusively in civil law contexts — Roman law texts, the Digest, and commentaries on continental inheritance systems. Researchers working in common law sources will rarely encounter it except in treatises or dictionaries that incorporate Roman law vocabulary for comparative purposes.
The primary corpus connection is to intestate succession doctrine and the civil law of kinship degrees. When tracing inheritance disputes in Louisiana, Quebec, or other mixed jurisdictions with civil law roots, researchers may encounter this term in older pleadings or doctrinal works. In purely common law jurisdictions, the concept exists but the Latin nomenclature was never adopted; the relationship would simply be described as "grandmother's sister" or "great-aunt" without a term of art.
The Digest citation — Dig. 38.10.10.15 — anchors the term in Justinian's compilation and confirms this is classical Roman law, not a medieval or early modern invention. Researchers consulting historical sources should be aware that the Digest's kinship tables in Book 38 provide the authoritative Roman framework for the entire family of matertera terms.
Because the term is so specific, it functions primarily as a marker of precision in a source: an author using matertera magna rather than "great-aunt" is almost certainly drawing on civil law or Roman law sources directly, which can help date or situate an unfamiliar document.
Historical Dictionary Support
Black's and Burrill's are in complete agreement, offering nearly identical definitions: a great-aunt; a grandmother's sister (aviæ soror), with shared citation to Dig. 38.10.10.15. This consistency reflects that the term is unambiguous and has no disputed meaning across the historical sources — it is a fixed point in Roman kinship taxonomy.
The Bouvier's entry reproduced here does not contain a definition for matertera magna; the text appears to be a misalignment in the source material, capturing instead a passage on maritime law. Researchers should treat Bouvier's as silent on this term rather than contradictory.
None of the historical dictionaries elaborate on how matertera magna interacted with specific succession rules or guardianship calculations under Roman law. For that analysis, researchers must go to the Digest itself or to civilian commentators such as Pothier or Domat.
Jurisdictional Note
The term has operative legal significance only in jurisdictions applying civil law inheritance rules derived from Roman sources. In Louisiana and historically in other American territories with French or Spanish legal heritage, such precise kinship terminology occasionally appears in succession proceedings. Common law jurisdictions have no equivalent term of art.