to come on like gangbusters (c. 1940) is from popular U.S. radio crime-fighting drama "Gang Busters" (1937-57) which always opened with a cacophony of sirens, screams, pistol shots, and jarring music.
gander
gandy dancer
gang
Gang of Four
gang-bang
gangbusters
Ganges
gangland
ganglia
gangling
ganglion