dodgems

Concise Oxford English Dictionary © 2008 Oxford University Press:
dodgem /ˈdɒʤəm/ (also dodgem car)

▶noun a small electrically powered car driven within an enclosure at a funfair, with the aim of bumping other such cars and avoiding being bumped by them.

– origin 1920s: US proprietary name (as Dodg'em), from the phr. dodge them.