a. - Cutting; divivding into two parts; as, a secant line.
a. - A line that cuts another; especially, a straight line cutting a curve in two or more points.
a. - A right line drawn from the center of a circle through one end of a circular arc, and terminated by a tangent drawn from the other end; the number expressing the ratio line of this line to the radius of the circle. See Trigonometrical function, under Function.