Definition
A mercedary is a person who hires another — that is, one who takes on the services of a worker or laborer in exchange for compensation. The term designates the hiring party in a contract of hire, as distinguished from the person hired.
Common Confusion
Mercedary (the hirer) is easily confused with mercenary (one who works for pay). The two terms share a common Latin root — merces, meaning wages or reward — but occupy opposite positions in the hiring relationship. A mercenary or hired worker performs the service; the mercedary pays for it. In some historical sources, particularly those translating from Latin or civil law originals, context is the only reliable guide to which party is meant. Researchers should verify the role of the party in question before assuming the term's application.
Why It Matters in Research
Mercedary is a rare technical term encountered almost exclusively in older legal texts and ecclesiastical or civil law discussions. Researchers working in medieval and early modern legal sources, Roman law commentaries, or canon law materials may encounter it in contexts involving contracts of service, hired labor, or the obligations running between employer and worker. The term does not appear in modern American or English statutory law, and its practical disappearance from legal usage by the nineteenth century means it will surface primarily in historical treatises and dictionaries rather than in reported cases.
The chief research trap is scope: mercedary describes the hiring party only — not the hired person (who would be termed the mercenary, locatarius, or simply the servant or employee depending on the source and period). Conflating the two produces a reversal of legal roles in any contract-of-hire analysis. Researchers reading Roman law commentary or its civil law descendants should note that the underlying concept corresponds to the locator in a locatio conductio operarum, the party who "places" the worker under contract.
Because the term is definitionally sparse in all available sources, researchers should not expect doctrinal elaboration within the mercedary entry of any historical dictionary. Substantive law on the rights and duties of the hiring party will be found under adjacent terms — hire, hiring, locatio conductio, master and servant, and employer — not under mercedary itself.
Historical Dictionary Support
Both Black's Law Dictionary editions consulted are in complete agreement and equally spare: "A hirer; one that hires." Neither edition provides doctrinal context, illustrative quotation, or cross-reference to related hiring law. This brevity is itself informative — the term was already archaic when Black compiled his dictionary and was included as a reference point for readers encountering it in older authorities, not as a term of active legal practice. No meaningful divergence exists between the two editions, and no expansion of the definition appears across versions. Researchers should treat these entries as identification aids rather than sources of substantive doctrine.