Origin: 1300–50; (noun) Middle English: a snap or bite, derivative of snacken to snap, bite; compare Middle Dutch snack a snap; (v.) derivative of the noun
c.1300, "to bite or snap" (of a dog), probably from M.Du. snacken "to snatch, chatter" (see snatch). The meaning "have a mere bite or morsel, eat a light meal" is first attested 1807; the noun in this sense is from 1757. Snack bar is attested from 1930.