Wiktionary
n. 1 The archery bow borne by Cupid in artistic representations, which curves inward at the centre and often outward at the ends. 2 The curve of the upper lip which resembles such a bow; the philtrum. 3 A similar curve carved in woodwork, etc.
Usage examples of "cupid's bow".
A classic French face, oval beneath a broad smooth brow, short straight nose, a delicate cleft in the small squared-off chin, and a cupid's bow mouth with a long upper lip.
She pouted her lips into a rosy cupid's bow and whistled like a snake charmer, at the same time slowly raising her forefinger in an unmistakably obscene gesture.
In skimpy dresses, their faces plastered with powder and rouge, their lips fashioned into caricatures of the Cupid's bow, they adored the manner in which the mouths of old peasants dropped open as they flounced by with their parasols.