Definition
In Roman law, a bar or fastening used to secure a door. The term appears in the Digest in the context of sale and property obligations, referring to physical fixtures — specifically, the hardware by which a door or gate was closed and secured. The plural form, *claustra*, extended to bars or barriers more generally.
The term has no active role in modern Anglo-American legal usage. Its relevance is strictly historical and philological, arising in the interpretation of Roman law sources, particularly passages from Justinian's Digest.
Common Language
Modern common usage (Wiktionary): A thin, irregular sheet of grey matter underneath the inner part of the neocortex on both sides of the brains of mammals; its exact function is not understood, but it is believed to facilitate coordination between senses.
Historical common usage (Webster's 1913): A thin lamina of gray matter in each cerebral hemisphere of the brain of man.
The anatomical term and the legal term are false cognates — they share a Latin root suggesting enclosure or barrier, but they arrived in entirely separate disciplines and carry no shared legal or interpretive significance. A researcher encountering *claustrum* in a legal source should not import any anatomical meaning; the legal sense is purely architectural and material.
Why It Matters in Research
Researchers working in Roman law sources, civil law traditions, or comparative legal history may encounter *claustrum* and *claustra* in texts derived from or commenting on the Digest. The specific passage cited in Burrill (Dig. 19.1.17) concerns the contract of sale and what fixtures or fittings pass with property — a question with genuine doctrinal weight in Roman property law. In that context, *claustra* functions as a concrete example of attached fixtures, analogous to the common law treatment of fixtures passing with a conveyance.
The main research trap is contextual confusion. Because *claustrum* also appears widely in ecclesiastical Latin — where it denotes the enclosure of a monastery or cloister — a researcher in canon law or ecclesiastical history sources may encounter the word carrying a completely different, institutional meaning. The monastic *claustrum* (the cloister or enclosed precinct) is architecturally adjacent to the Roman law meaning but legally distinct. Neither sense maps onto the anatomical use found in modern scientific dictionaries.
In civil law jurisdictions with Roman law foundations, terms like *claustra* or related forms may appear in older codes or commentaries dealing with property, lease, or sale. Researchers consulting French, Spanish, or Louisiana civil law sources from the eighteenth or nineteenth century should be alert to this terminology in passages addressing what passes with a building or land sale.
The corpus footprint of this term in common law sources is minimal. It surfaces almost exclusively in Latin quotation, glossary work, and comparative Roman law commentary rather than in case law or statute.
Historical Dictionary Support
Burrill is the only shelf source to treat *claustrum* as a legal term, and his entry is spare: a one-line definition pointing to the Roman law bar or fastening, with citation to Digest 19.1.17. This is consistent with the term's limited penetration into English legal vocabulary — Burrill includes it as a civil law reference point rather than a term of art in use in Anglo-American practice.
No other major historical legal dictionaries in the Law Mind corpus (Bouvier, Black, Wharton) carry an entry for *claustrum* as a legal term. The absence is informative: this is a term that traveled with Roman law scholarship rather than with common law practice. Burrill's inclusion reflects his broader comparative and civil law coverage, which distinguishes his dictionary from more common-law-centric competitors.
The Digest citation is genuine and traceable. Digest 19.1.17, attributed to Ulpian, addresses obligations arising from sale contracts — including questions about what physical elements of a property the seller is obligated to transfer or preserve. The reference to *claustra* in that context illustrates the Roman law of fixtures and attached property, a small but real doctrinal point.
Jurisdictional Note
Relevant primarily to civil law jurisdictions and to academic Roman law research. No common law jurisdiction treats *claustrum* as a term of operative legal art.