whimwham (n.)

also flimflam, 1530s, a contemptuous echoic construction, perhaps connected to some unrecorded dialectal word from Scandinavian (compare Old Norse flim "a lampoon"). From 1650s as a verb. Related: Flim-flammer.

1640s, "play on words, pun," shortened from whimwham "fanciful object" (q.v.). Meaning "caprice, fancy, sudden turn or inclination of the mind" first recorded 1690s, probably a shortened form of whimsy.

c. 1600, probably related to whimwham.