Tredecim

Part of speech: noun

Definitions

1. A cardinal number denoting the quantity thirteen; the sum total obtained when counting twelve and adding one more; representing a count or sequence positioned after twelve and before fourteen
2. An expression indicating the numeric value that follows twelve and precedes fourteen in an ordered series; used in counting, measuring, or labeling the thirteenth item or unit; a numeral denoting one more than a dozen
3. A term for the number that comes immediately after twelve and before fourteen; often employed in enumeration, mathematics, or identifying the thirteenth element in a list; signifying the amount equivalent to a dozen plus one

Etymology: "Tredecim" is the Latin word for thirteen, built from "tres" (three) and "decem" (ten), so it literally means "three-and-ten," the same pattern as the English "thirteen," which is itself a compound of "three" and "-teen" from the Old English "-tene," meaning "ten." The Latin form is a fully Latin compound, and it was used as a cardinal number in Roman counting, long before English had any word for the figure. Two uses of the word survive in English. In the Latin-derived technical vocabulary of mathematics and biology, "tredecim" appears in combining forms, and in older scholarly writing it occurs as a label for the thirteenth item in a sequence. The number itself is a useful reminder that Latin forms from the same stem as "decimal" and "decade" built all the Roman counting words, so the English "thirteen" and the Latin "tredecim" are structural cousins rather than direct borrowings.

Synonyms: thirteen (Latin), XIII, 13