2. (Mech.)
Defn: A long spar or beam, projecting from the mast of a derrick, from the outer end of which the body to be lifted is suspended.
3. A pole with a conspicuous top, set up to mark the channel in a river or harbor. [Obs.]
4. (Mil. & Naval)
Defn: A strong chain cable, or line of spars bound together, extended across a river or the mouth of a harbor, to obstruct navigation or passage.
5. (Lumbering)
Defn: A line of connected floating timbers stretched across a river, or inclosing an area of water, to keep saw logs, etc., from floating away. Boom iron, one of the iron rings on the yards through which the studding-sail booms traverse. — The booms, that space on the upper deck of a ship between the foremast and mainmast, where the boats, spare spars, etc., are stowed. Totten.
BOOM
Boom (boom), v. t. (Naut.)
Defn: To extend, or push, with a boom or pole; as, to boom out a sail; to boom off a boat.
BOOM Boom (boom), v. i. [imp. & p. p. Boomed, p. pr. & vb. n. Booming.] Etym: [Of imitative origin; cf. OE. bommen to hum, D. bommen to drum, sound as an empty barrel, also W. bwmp a hollow sound; aderyn y bwmp, the bird of the hollow sound, i. e., the bittern. Cf. Bum, Bump, v. i., Bomb, v. i.]