What's the "een" in Halloween?
dance performed to music in triple time, 1781, from German Waltzer, from walzen "to roll, dance," from Old High German walzan "to turn, roll," from Proto-Germanic *walt- (cf. Old Norse velta), from PIE root *wel- "to turn, revolve" (see volvox). Described in 1825 as "a riotous and indecent German dance."
1794, from waltz (n.). Meaning "to move nimbly" is recorded from 1862. Related: Waltzed; waltzing.