Merriam-Webster's Collegiate® Dictionary, 11th Edition
BRIEF
I. adjective
Etymology: Middle English bref, breve, from Anglo-French bref, brief, from Latin brevis; akin to Old High German murg short, Greek brachys
Date: 14th century
short in duration, extent, or length,
2. concise , curt , abrupt , briefness noun
II. noun
Etymology: Middle English bref, from Anglo-French, from Medieval Latin brevis, from Late Latin, summary, from Latin brevis, adjective
Date: 14th century
1. an official letter or mandate, a specific instruction or responsibility ,
2. a concise article, synopsis , summary , a concise statement of a client's case made out for the instruction of counsel in a trial at law, an outline of an argument, short snug pants or underpants,
III. transitive verb
Date: 15th century
to make an abstract or abridgment of,
2. to give final precise instructions to, to coach thoroughly in advance, to give essential information to, to discuss (as a military operation) in a briefing , briefer noun