Meaning

noun a deep prolonged loud noise

noun a state of economic prosperity

noun a sudden happening that brings good fortune (as a sudden opportunity to make money)

originOnomatopoeic, perhaps borrowed; compare German bummen, Dutch bommen (“to hum, buzz”). The sense "a period of economic growth" is generally taken to derive from the sense "a rapid expansion", although other origins have also been suggested.

Etymology from Wiktionary, CC BY-SA 3.0