present participle of nip at

simple past tense and past participle of nip at

(Ireland, UK, idiomatic, informal) Nude.

To bite or pinch with small actions. / (of poor weather) To be cold; to be bitingly cold. / (idiomatic) To sip a drink (usually alcoholic) in small amounts.

plural of cat-nip

plural of nip and tuck

To remove a bud [from a plant] to prevent flower and fruit from forming. / (idiomatic) To stop something at an early stage.

Minor cosmetic surgery that tightens loose skin.

With the advantage changing hands, or shifting back and forth among the available alternatives.

(idiomatic) So evenly matched that the advantage shifts from one to the other, and the outcome is uncertain.