1670s, "officer in command of a brigade," from French brigadier, from brigade "body of soldiers" (see brigade). Brigadier-general is the fuller form of the title.
Entries linking to brigadier
brigade n.
subdivision of an army, 1630s, from French brigade "body of soldiers" (14c.), from Italian brigata "troop, crowd, gang," from brigare "to brawl, fight," from briga "strife, quarrel," perhaps of Celtic (compare Gaelic brigh, Welsh bri "power"), from PIE root *gwere- (1) "heavy." Or perhaps from Germanic.