Definition
In law, "thousand" ordinarily denotes the number 1,000 — ten times one hundred. The term appears most often in legal instruments as a quantity marker: in contracts specifying goods, in statutory fine schedules, in valuation thresholds, and in rate expressions such as "per thousand" used in insurance, taxation, and municipal finance. In these standard contexts, "thousand" carries its plain arithmetic meaning without special legal content.
The legal significance of the term arises not from any general legal redefinition, but from the narrow but well-established principle that trade custom or usage can assign "thousand" a meaning that departs entirely from its ordinary numerical sense. Where such a custom exists and is sufficiently established, courts will give effect to the trade meaning over the plain meaning.
Common Language
Modern common usage (Wiktionary): A numerical value equal to 1,000 = 10 × 100 = 10³.
Historical common usage (Webster's 1913): The number of ten hundred; a collection or sum consisting of ten times one hundred units or objects. Hence, indefinitely, a great number.
The gap between common and legal meaning is not definitional in the abstract — "thousand" in law is ordinarily 1,000 — but the legal framework permits trade usage to override that number entirely. A buyer contracting for "a thousand" rabbits under a trade custom that defines the unit as 1,200 (one hundred dozen) has contracted for 1,200, not 1,000, regardless of the word's plain meaning. This potential for displacement by custom is the one point where common understanding of the term becomes legally unreliable.
Common Confusion
The term invites a false sense of certainty. Because "thousand" appears self-defining, parties and researchers may assume it is immune to interpretive dispute. It is not. The operative question in a contract or instrument dispute is not what "thousand" means in the abstract, but what it means in the relevant trade, market, or custom at the time of contracting. The word's apparent mathematical precision can obscure this inquiry entirely if the reader does not know to look for it.
Why It Matters in Research
The research value of this entry is almost entirely confined to one issue: trade usage as a modifier of numerical terms in contract disputes. Researchers encountering disputes over quantity in historical contracts — particularly in agricultural commodities, livestock, timber, textiles, fish, and other trades with established unit customs — should not assume that named quantities correspond to their arithmetic values. The rabbit example from Bouvier (one thousand rabbits = 1,200 under trade custom) is illustrative of a broader phenomenon affecting many historical industries.
In historical sources, "thousand" in trade instruments may reflect a "long thousand" or other customary unit rooted in pre-metric counting systems, where certain commodities were counted by the gross, the hundred-and-twenty, or other non-decimal groupings. Legal disputes in nineteenth-century English and American courts addressed this repeatedly. Researchers working with pre-twentieth-century commercial contracts should treat apparent quantity terms as potentially customary rather than arithmetic.
In modern research contexts, "thousand" most commonly appears in statutory thresholds (jurisdictional amounts, fine schedules, damage caps), insurance rate tables (premium per thousand of coverage), and tax instruments (millage rates expressed as dollars per thousand of assessed value). In these contexts, plain arithmetic meaning governs. The trade-usage issue is predominantly a historical contracts problem.
Corpus researchers should note that "per thousand" in insurance and tax instruments is a rate expression with its own interpretive conventions — the denominator establishes the base unit for calculation, and errors in identifying the base can produce significant valuation mistakes.
Historical Dictionary Support
Bouvier's entry is brief but pointed. It makes no claim about "thousand" as a general legal term — correctly so, because outside of trade usage the word has no special legal definition. Bouvier's entire contribution is the trade custom principle: that custom or usage of trade can give "thousand" a meaning peculiar to a given market, citing the rabbit case (3 B. & Ad. 728) as authority. This reflects the broader common law principle that trade terms in commercial instruments are interpreted according to the usage of the relevant trade, a rule well established in both English and American contract law.
What historical dictionaries do not supply, and what researchers should seek elsewhere, is a systematic account of which trades historically used non-standard thousands. Bouvier names only rabbits. The phenomenon extended further. Historical commodity dictionaries, treatises on mercantile customs, and industry-specific legal materials are better sources for that catalog.
Jurisdictional Note
The trade-usage interpretive principle applies in both English and American common law traditions and is codified in modern American law under the Uniform Commercial Code's course of dealing and usage of trade provisions. The specific trade customs that give "thousand" a non-standard meaning are local and industry-specific; no general jurisdictional rule governs their content.