Definition
A French monetary unit equal to one-tenth of a franc, worth approximately two cents in the period when the term appeared in legal literature. The decime surfaces in legal dictionaries primarily as a unit of account or reference point in matters involving French currency — relevant to colonial-era transactions, international commercial disputes, prize cases, and property records touching French legal territories.
Common Language
Webster's 1913: "A French coin, the tenth part of a franc, equal to about two cents."
Wiktionary flags an alternate English usage — "decime" as a synonym for tithing, a subdivision of a hundred in medieval English administrative geography.
The two meanings are entirely unrelated and arise from different linguistic lineages. A researcher encountering "decime" in a French or civil-law context should understand it as currency. A researcher encountering it in records concerning medieval English land administration or taxation may be looking at the tithing sense. Conflating them would be a significant error. The legal dictionaries in the Law Mind corpus address only the French coin meaning.
Common Confusion
The Wiktionary tithing sense of "decime" does not appear in any of the three source dictionaries. Researchers working in English ecclesiastical records, hundred-court rolls, or pre-Conquest administrative documents should consult entries for TITHING and HUNDRED rather than treating this dictionary entry as authoritative for that usage. The legal dictionary tradition — Black's, Rapalje & Lawrence, Bouvier — uses "decime" exclusively for the French monetary unit.
Why It Matters in Research
Decime appears in legal records principally in three contexts: (1) French colonial and post-colonial property and commercial transactions, particularly in Louisiana, where French civil-law heritage means French monetary denominations persisted in older instruments; (2) prize court and admiralty proceedings involving French vessels or cargo, where valuations in French currency required conversion; and (3) international treaty and debt instruments of the late eighteenth and early nineteenth centuries.
Researchers should note that the franc itself was not established until 1795, and the decime as one-tenth of a franc is therefore a specifically post-Revolutionary French monetary unit. Encountering "decime" in a document predating the French Revolution signals either anachronistic language, a later transcription, or a different monetary system entirely. Cross-reference with contemporary exchange rate tables when valuation matters — the "nearly two cents" approximation in Black's reflects a particular historical moment and should not be applied mechanically to documents from different periods.
Louisiana legal records are the most likely domestic source for this term in American legal research. French-language instruments from the territorial and early statehood periods may denominate values in francs and decimes. Researchers unfamiliar with civil-law notarial practice may encounter these records without clear guidance on conversion or legal significance.
Historical Dictionary Support
Black's Law Dictionary (both the first and second editions) and Rapalje & Lawrence are in complete agreement: the decime is a French coin worth one-tenth of a franc, approximately two cents. Rapalje & Lawrence attributes the definition to Bouvier, indicating this entry migrated through the standard American legal dictionary tradition without meaningful revision.
Both editions of Black's append the Latin maxim "Decipi quam fallere est tutius" ("It is safer to be deceived than to deceive") with a citation to Lofft, 396 — an 18th-century English reports volume. This maxim has no substantive connection to the coin definition and appears to have been included as an alphabetical neighbor (both beginning with "deci-") rather than as a legal gloss on the term. Researchers should not treat the maxim as legally related to the monetary unit.
What the historical dictionaries do not address: conversion methodology, the relationship between the decime and pre-Revolutionary French monetary units (such as the livre and sol), or any guidance on how courts actually handled franc-denominated valuations. For practical research into those questions, contemporary commercial treatises and Louisiana civil materials are more useful than the dictionary tradition.
Jurisdictional Note
The decime is most legally significant in Louisiana, where French civil-law heritage and pre-statehood French instruments mean the term has actual transactional history in domestic American records. Elsewhere in the United States, it appears almost exclusively in federal admiralty and international commercial contexts.