Bombardier \Bom`bar*dier"\, n. [F. bombardier.]

(Mil.)
   (a) One who used or managed a bombard; an artilleryman; a gunner. [Archaic]
   (b) A noncommissioned officer in the British artillery.

Bombardier beetle (Zo["o]l.), a kind of beetle (Brachinus crepitans), so called because, when disturbed, it makes an explosive discharge of a pungent and acrid vapor from its anal glands. The name is applied to other related species, as the B. displosor, which can produce ten or twelve explosions successively. The common American species is B. fumans.

Source: Webster's Revised Unabridged Dictionary (1913)