privateer

PRIVATEE'R, n. [from private.] A ship or vessel of war owned and equipped by a private man or by individuals, at their own expense, to seize or plunder the ships of an enemy in war. Such a ship must be licensed or commissioned by government, or it is a pirate.

PRIVATEE'R, v.i. To cruise in a commissioned private ship against an enemy, for seizing their ships or annoying their commerce.