·vi To make a hollow sound, as of waves or cannon.
II. Boom ·noun A pole with a conspicuous top, set up to mark the channel in a river or harbor.
III. Boom ·vi To have a rapid growth in market value or in popular favor; to go on rushingly.
IV. Boom ·noun A hollow roar, as of waves or cannon; also, the hollow cry of the bittern; a booming.
V. Boom ·vi To cry with a hollow note; to make a hollow sound, as the bittern, and some insects.
VI. Boom ·vt To extend, or push, with a boom or pole; as, to boom out a sail; to boom off a boat.
VII. Boom ·vi To rush with violence and noise, as a ship under a press of sail, before a free wind.
VIII. Boom ·noun 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.
IX. Boom ·vt To cause to advance rapidly in price; as, to boom railroad or mining shares; to create a "boom" for; as to boom Mr. C. for senator.
X. Boom ·noun A line of connected floating timbers stretched across a river, or inclosing an area of water, to keep saw logs, ·etc., from floating away.
XI. Boom ·noun A long pole or spar, run out for the purpose of extending the bottom of a particular sail; as, the jib boom, the studding-sail boom, ·etc.
XII. Boom ·noun 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.
XIII. Boom ·noun A strong and extensive advance, with more or less noisy excitement;
— applied colloquially or humorously to market prices, the demand for stocks or commodities and to political chances of aspirants to office; as, a boom in the stock market; a boom in coffee.