Definition
De una parte (Latin: "of one part") is a phrase used to describe a unilateral deed — a legal instrument in which only one party grants something, conveys property, or binds itself to perform an obligation in favor of another. The grantor acts; the other party receives. No mutual exchange of promises or obligations is required on the face of the instrument. The term functions as a classifier distinguishing this type of deed from bilateral instruments in which both parties undertake obligations to each other.
Common Confusion
De una parte is most readily confused with its counterpart, inter partes ("between parties"), which describes a deed in which two or more parties each undertake obligations and both are formally named as contracting sides. The distinction matters because inter partes instruments create mutual covenants enforceable by either party, while a deed de una parte typically reflects a one-directional transfer or promise — a grant, a gift, or a bond running from grantor to grantee without a reciprocal undertaking by the receiving party. Researchers encountering both phrases in historical conveyancing documents should not assume either implies the presence or absence of consideration; the distinction is structural, not about whether value passed.
Why It Matters in Research
This is an archaic Latin classifier found almost exclusively in pre-twentieth-century conveyancing literature, deed precedents, and treatises on real property. Researchers will not encounter de una parte as operative language in modern instruments; it appears instead as analytical vocabulary used by commentators — including Bouvier — to categorize deeds by their structural form.
The primary research trap is treating de una parte as a term of art with independent doctrinal weight. It has none. It is a descriptive label. Its significance is comparative: it tells you what kind of deed you are looking at relative to an inter partes instrument, not what legal consequences attach. Do not expect statutory definitions, case law construing the phrase directly, or regulatory usage.
Researchers working with historical land records, colonial-era conveyances, or early nineteenth-century equity pleadings may encounter the phrase in indices, headnotes, or treatise footnotes. When it appears, the immediate analytical question is whether the instrument created mutual obligations — if not, de una parte is the applicable description, and the researcher should look to the law of gifts, grants, and voluntary conveyances rather than to contract doctrine governing bilateral agreements.
The corpus connection to inter partes is essential. Neither term can be fully understood without the other. Any research path that begins with de una parte should move immediately to inter partes for the full structural picture.
Historical Dictionary Support
Both editions of Black's Law Dictionary reproduce identical language, tracing the definition to Bouvier's Institutes (no. 2001). The definition is narrow and stable across both editions: a deed de una parte is one in which only one party grants, gives, or binds itself to do something for another. Neither edition elaborates beyond this single sentence of substance. The reliance on Bouvier signals that by the time Black's was compiled, the term was already receding from active legal usage and persisting mainly as learned vocabulary preserved in treatise literature.
What the historical dictionaries do not address: the phrase's relationship to consideration doctrine, its interaction with seal requirements for deeds, or how courts treated unilateral instruments when disputes arose. These gaps reflect the phrase's purely descriptive function — it categorized instruments without generating its own body of interpretive case law.
Jurisdictional Note
The term appears in English and American common law treatise literature without jurisdiction-specific variation. Because it was never operative drafting language in statutes or court rules, no meaningful jurisdictional split exists. Researchers in civil law jurisdictions will find no parallel usage.