"to pinch sharply, to bite," late 14c., related to M.L.G. nipen "to nip," Du. nijpen, but the exact evolution of the stem is obscure. Related: Nipped; nipping. The noun is attested from 1550s. To nip (something) in the bud in the figurative sense is first recorded c.1600. Nip and tuck "a close thing" is recorded from 1832, perhaps from sailing or tailoring.
"small measure of spirits," 1796, shortening of nipperkin (1671) "quantity of liquor of a half pint or less," possibly of Du. or Low Ger. origin and related to nip (v.).