Entry 1 sense Webster, 1913 Cosecant /(k?-s?"k?nt)/ · Co·se·cant · IPA /ˈkoʊˌsiːkənt/ 01 n. The secant of the complement of an arc or angle. See Illust. of Functions. 1. The secant of the complement of an arc or angle. See Illust. of Functions.(Trig.) See: Functions