Is it ensure, insure, or assure?
"amorous, flirtatious person," 1690s, originally of both sexes (as it was in French), from French coquet (17c.), diminutive of coq "cock" (see cock (n.1)). A figurative reference to its strut or its lust. The distinction of fem. coquette began c.1700, and use in reference to males has faded out since.