c. 1600, "to flap," probably a variant of flap with a duller, heavier sound. Sense of "fall or drop heavily" is 1836; that of "collapse, fail" is 1919; though the figurative noun sense of "a failure" is recorded from 1893. Related: Flopped; flopping.
flop (n.)
1823, "act of flopping; any action that produces the sound 'flop;' the sound itself," from flop (v.). Figurative sense of "a failure; that which is a failure" is by 1893, from the notion of a sudden break-down or collapse. Extended form flopperoo attested from 1936. The Fosbury flop high-jumping technique (1968) is so called in reference to U.S. athlete Dick Fosbury (b.1947), who used it to win the 1968 Olympic gold medal.
例文
1. Very good use of the term flip- flop ,by the way.
その立場は確固としておらず、常にflip- flop をしている人はそうは言えません!
2.It is the public who decide if a film is a smash or a flop .
映画の成否は公衆にかかっている。/
3.He seemed so sure of his decision,how could he flip- flop so dramatically now?