BOOM

(Dutch boom, a tree.) A nautical term, signifying a long pole run out from any part of a ship to stretch the bottoms of particular sails; v/hencB jib-boom, main-boom, studdingsail-boom, . Boom. In Marine Fortification, signifies a strong chain or cable stretched acro the mouth of a harbour or river, to prevent the enemy's ships from entering, and having a number of poles, bars, . fastened to it; whence the name. [s. 167]