late 15c., "quick, sudden bite or cut," from Dutch or Low German snappen "to snap," probably related to Middle Low German or Middle Dutch snavel "bill, beak," from West Germanic *snu-, an imitative root forming words having to do with the nose (see snout).
As an adjective from 1790. Commonly used to indicate instantaneous action, as in snap judgment (1841). Sense of "quick movement" is first recorded 1630s; that of "something easily done" is 1877. Meaning "brief or sudden spell" of weather (usually cold) is from 1740. Meaning "catch or fastener that closes with a snapping sound" is from 1815. The card game name is attested from 1881, from a call used in the game. Meaning "a snap-shot" is from 1894. U.S. football sense is from 1912, earlier snap-back (1880), which also was a name for the center position. Snap, Crackle and Pop, cartoon characters associated with Kellogg breakfast cereal Rice Krispies, are from 1940.