[co.tan.gent] n [NL cotangent-, cotangens, fr. co- + tangent-, tangens tangent] (1635) 1: a trigonometric function that for an acute angle is the ratio between the leg adjacent to the angle when it is considered part of a right triangle and the leg opposite
2: a trigonometric function cot A that is equal to the cosine divided by the sine for all real numbers A for which the sine is not equal to zero and is exactly equal to the cotangent of an angle of measure A in radians