I. (ˈ)kō+ noun
( -s )
Etymology: New Latin cosecant-, cosecans, from Latin co- + secant-, secans, present participle of secare to cut — more at saw
: the distance between the vertex of an angle and any other point on its terminal side divided by the nonzero ordinate of this point, the vertex coinciding with the origin of a plane rectangular coordinate system and the initial side of the angle coinciding with the positive x-axis — abbr. cosec or csc
II. noun
: 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