bri·gade / briˈgād/ • n. a subdivision of an army, typically consisting of a small number of infantry battalions and/or other units and often forming part of a division: he commanded a brigade of 3,000 men. ∎  an organization with a specific purpose, typically with a military or quasi-military structure: the local fire brigade. ∎  [in sing.] inf., often derog. a group of people with a common characteristic or dedicated to a common cause: the anti-smoking brigade.

brigade XVII. — (O)F. brigade — It. brigata troop, company, f. brigare be busy with, f. briga strife, contention, which has been referred to Gmc. *brekan BREAK; see -ADE.
So brigadier XVII. — F.

Brigade

BRIGADE. A military formation of two or more regiments, generally temporary, and commanded by a brigadier in the British army or a brigadier general in the American army. (During the Revolution the terms "regiment" and "battalion" were virtually synonymous.)

Brigade

a company or band of people; a body of troops; any body of persons acting together for a purpose, e.g., fire brigade.

Examples: brigade of firemen; of papists, 1649; of people, 1650; of foot (soldiers) 1642; of sappers, 1806; of trappers, 1837.