boom (v.)
mid-15c., earliest use was for bees and wasps, probably echoic of humming. The meaning "make a loud noise" is 15c. Compare bomb. Meaning "to burst into prosperity" (of places, businesses, etc.) is 1871, American English. Related: Boomed; booming. Boom box first attested 1978.
boom (n.1)
"long pole," 1540s, from Scottish boun, borrowed from Dutch boom "tree, pole, beam," from a Middle Dutch word analogous to Old English beam (see beam (n.)).
boom (n.2)
in the business sense, 1873, sometimes said to be from boom (n.1), from the nautical meaning "a long spar run out to extend the foot of a sail" -- a ship "booming" being one in full sail. But it could just as well be from boom (v.) on the notion of "suddenness."