c. 1400, "a snatch or snap" (especially that of a dog), from snack (v.). Later "a snappish remark" (1550s); "a share, portion, part" (1680s; hence old expression go snacks "share, divide; have a share in"). Main modern meaning "a bite or morsel to eat hastily" is attested from 1757. Snack bar is attested from 1923. Commercial plural form snax attested from 1942 in the vending machine trade.