secant, in mathematics. 1 In geometry, a secant is a straight line cutting a curve or surface. If it intersects the curve in two different points, as in the secant of a circle, the segment of the secant between the points is called a chord. The limiting position of a secant, if such a limit exists, is called the tangent to the curve or surface at that point. 2 A trigonometric function. See trigonometry.

Secant is a term in mathematics. It comes from the Latin secare (to cut). It can refer to:

• a secant line, in geometry
• the trigonometric function called secant
• the secant method, a root-finding algorithm in numerical analysis