c. 1600, "talkative, nimble in talk;" 1670s, "displaying unbecoming levity," apparently an extended form of flip (v.). The ending is perhaps modeled on other adjectives in -ant or a relic of the Middle English present participle ending -inde. Shortened form flip is attested from 1847. Related: Flippantly.
flintstone
flinty
flip
flip-flop
flippancy
flippant
flipper
flip-top
flirt
flirtation
flirtatious