Definition
Una is a Latin term meaning "one" or "together," appearing in several Latin legal maxims and compound phrases used in historical common law and civil law texts. It does not function as a standalone legal term of art in modern law but appears as a component of Latin phrases that carry legal significance, most notably in expressions concerning joint or unified action, single heirship, or undivided rights.
Common Confusion
Una should not be confused with UNUS (masculine form) or with any of the compound phrases in which it appears. Encountering "una" in a primary source almost always means the full phrase is present nearby; isolating the word artificially distorts the meaning. Researchers working with Scots law materials should note that Erskine's usage, referenced in the Burrill source text (though in a passage likely misassigned here), concerns the king's role as ultimate heir — a concept properly understood under ultimus haeres, not under una.
Why It Matters in Research
Researchers encountering "una" in historical legal sources should treat it as a Latin modifier rather than a discrete legal term. It appears most often as part of compound phrases — una voce (with one voice; unanimously), una cum (together with), and related constructions — that carry procedural or substantive meaning in pleading records, conveyancing instruments, and early law reports. Misreading una as a standalone term rather than a component of a phrase will produce dead ends in index searches. When working in Burrill or similar historical dictionaries, cross-referencing to the relevant complete phrase (e.g., una voce, una cum) will yield more usable results than searching under "una" alone.
Anderson's Dictionary of Law provides no independent entry, instead redirecting to UNUS — the masculine singular form of the same Latin root. This is a signal that the historical dictionaries treat una primarily as a grammatical variant, not an independent legal concept. Researchers should consult UNUS for any substantive historical dictionary treatment of the underlying concept of singularity or unity in legal contexts.
The Burrill entry nominally filed under "una" in the source material is almost certainly a cataloging artifact: the text quoted — concerning ultimi haeredes (last heirs) and the lord as ultimate heir, citing Glanville and Erskine — belongs to a different headword and has been associated with "una" only through a pagination or indexing error in the digitized source. Researchers should not treat that passage as defining or illustrating "una." Its substantive content belongs under ULTIMUS HAERES or ESCHEAT.
Historical Dictionary Support
Anderson redirects without comment to UNUS, indicating that nineteenth-century American legal lexicography did not treat una as independently significant. Burrill's associated text, as noted above, is almost certainly misattributed due to a source-text artifact and should not be relied upon as a definition of una. Neither dictionary offers a substantive gloss on the term itself.
Historical legal Latin glossaries outside the Law Mind corpus — including those appended to older editions of Bouvier's Law Dictionary and Black's early editions — treat una only in its compound forms. This pattern is consistent: the term has lexical significance only in context.
Jurisdictional Note
Latin compound phrases using una appear across common law and civil law jurisdictions but with varying frequency. Scots law and early American equity practice make heavier use of Latin maxims than modern common law pleading, where such phrases have been largely superseded by English equivalents.