cosecant

noun

co·​se·​cant (ˌ)kō-ˈsē-ˌkant 

-kənt

1

: a trigonometric function that for an acute angle is the ratio between the hypotenuse of a right triangle of which the angle is considered part and the leg opposite the angle

2

: a trigonometric function csc θ that is the reciprocal of the sine for all real numbers θ for which the sine is not zero and that is exactly equal to the cosecant of an angle of measure θ in radians

Word History

Etymology

New Latin cosecant-, cosecans, from co- + secant-, secans secant

First Known Use

circa 1706, in the meaning defined at sense 1