Definition
A Latin verb from the Roman civil law tradition, meaning to define, to explain, or to set down a rule. In legal usage, *definire* carried two related but distinct senses: (1) to explain what a thing is (*quid res sit explicare*) — that is, to set out the nature or meaning of a subject or concept; and (2) to lay down a rule or principle as a matter of settled law (*pro regula aliquid statuere*). The term appears in the Digest and in civil law lexica as a term of juristic method rather than a term of substantive doctrine — it describes what jurists and legislators do when they articulate legal norms, not the norms themselves.
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Common Language
Modern common usage (Wiktionary): *Definire* is the Latin infinitive from which the English verb "to define" descends, meaning to fix the limits or boundaries of something, or to state the exact meaning of a word or concept.
Historical common usage (Webster's 1913): "Define" — To fix the bounds of; to determine with precision; to mark out with distinctness; to ascertain or explain the meaning of.
The gap between common and legal meaning here is less about divergence than about precision of context. In ordinary English, "to define" is a general act of explanation. In Roman civil law usage, *definire* carried methodological weight: it described a specific juristic act — the authoritative articulation of a legal rule or concept by a jurist or magistrate. The term thus appears not in the vocabulary of facts or parties, but in the vocabulary of legal reasoning and rule-formation.
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Why It Matters in Research
Researchers encountering *definire* in historical legal sources — particularly translations of or commentaries on the Digest and other Corpus Juris Civilis materials — should treat it as a term of legal methodology rather than a term with substantive doctrinal content. It signals that a jurist is performing the act of rule-articulation or concept-clarification, and its presence often marks passages that later commentators treated as authoritative statements of principle.
The Digest citation associated with this term (Dig. 34, 7, 1, pr.) concerns legacies of uncertain objects and their interpretation — a context in which the need to define the subject matter of a bequest was a practical legal problem, not merely a semantic one. Researchers working with civilian property law, succession, or contract doctrine in historical sources will encounter *definire* in contexts where the definition of a legal object or category carries direct operative consequences.
A particular trap in historical sources: early English common law treatises occasionally absorbed civilian vocabulary imprecisely. A common law author using "define" in a methodological sense may be echoing civilian usage of *definire* without signaling the borrowing. Awareness of the civilian genealogy of the term helps researchers identify passages of indirect civilian influence in ostensibly common law texts.
In Law Mind corpus materials, *definire* is most likely to appear in Latin-language civil law sources, in civilian glossaries, and in early modern English treatises drawing on Roman law foundations. It will rarely appear as a term of art in purely English-language common law materials.
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Historical Dictionary Support
Burrill's Law Dictionary is the primary shelf source for this term. Burrill traces *definire* to its Latin components (*de* + *finire*, from *finis*, a bound or limit) and accurately captures both senses of the term: explanation of a thing's nature, and promulgation of a rule. He cites Calvinus's *Lexicon Juridicum* for both senses and references Digest 34, 7, 1, pr. for the second.
No other historical dictionaries in the current source set address this term. Burrill's entry, though brief, is reliable. It correctly situates *definire* as a civilian term and does not attempt to map it onto common law equivalents — an appropriate restraint. Researchers should note that the *Lexicon Juridicum* of Johannes Calvinus (1612) is the intermediary source Burrill cites; that work is itself a significant reference for civil law vocabulary and can be consulted directly for fuller treatment of the term's usage in Roman and early modern legal writing.
What the historical dictionary sources do not address is the methodological significance of *definire* as a juristic act — the distinction between merely explaining a concept and authoritatively laying down a rule. That distinction matters in understanding the structure of Roman juristic argument and should not be collapsed when translating or interpreting classical sources.
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