I. (ˈ)kō+ noun
Etymology: New Latin cotangent-, cotangens, from co- + tangent-, tangens tangent
: the abscissa of any point except the vertex on the terminal side of an angle divided by the nonzero ordinate of the 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. cot or ctn
II. noun
: a trigonometric function cot θ that is equal to the cosine divided by the sine for all real numbers θ for which the sine is not equal to zero and is exactly equal to the cotangent of an angle of measure θ in radians