Why is the ninth month called September?
mid-15c., probably imitative of a light blow with a whip. Earliest recorded use is in phrase not worth a flykke "useless." As slang for "film," it is first attested 1926, a back-formation from flicker (v.), from their flickering appearance.
1816, from flick (n.); meaning "quick turn of the wrist" is from 1897, originally in cricket. Related: Flicked; flicking.
[1920s+; fr the flickering of early movie images]