flightiest
adj. (尤指女人或其行為)輕浮的,朝三暮四的,反覆無常的( flighty的最高階 )
If you say that someone is flighty, you disapprove of them because they are not very serious or reliable and keep changing from one activity, idea, or partner to another.
Isabelle was a frivolous little fool, vain and flighty.
伊莎貝爾是個輕佻、沒頭腦的小女人,非常虛榮又反覆無常。