- brief (adj.)
- late 13c., from L. brevis (adj.) "short, low, little, shallow," from PIE *mregh-wi-, from base *mregh-u- "short" (cf. Gk. brakhys "short," O.C.S. bruzeja "shallow places, shoals," Goth. gamaurgjan "to shorten").
- brief (n.)
- from L. breve (gen. brevis), noun derivative of L. adj. brevis (see brief (adj.)) which came to mean "letter, summary" (specifically a letter of the pope, less ample and solemn than a bull), and came to mean "letter of authority," which yielded the modern, legal sense of "summary of the facts of a case" (1630s). The verb meaning "to give instructions or information to" (1866) was originally "to instruct by a brief" (1862); hence briefing, first attested 1910 but popularized by WWII pre-flight conferences.