flighty

adj (-ier, -iest) (esp of a woman or her behaviour) changeable and unreliable; not serious （尤指女子或其行为）反覆无常的, 轻浮的.

flexibility, flexible, flexibly, flexitime, flibbertigibbet, flick, flick-knife, flicker, flier, flier (also flyer), flies, flight, flight attendant, flight lieutenant, flight path, flight sergeant, flight simulator, flight-deck, flight-recorder, flightless, flimsily, flimsiness, flimsy, flinch, fling, flint, flintlock, flinty, flip, flip side, flip-flop, flippancy, flippant, flippantly, flipper, flipping, flirt, flirtation, flirtatious, flit,