ETYM Cf. French sécante. Related to Secant.
1. A straight line that intersects a curve at two or more points.
2. Ratio of the hypotenuse to the adjacent side.
Cutting (line), especially one cutting curve at two points; radius produced through one end of arc to meet tangent drawn to other end; ratio of this line to radius (abbreviated as sec.).
In trigonometry, the function of a given angle in a right-angled triangle, obtained by dividing the length of the hypotenuse (the longest side) by the length of the side adjacent to the angle. It is the reciprocal of the cosine (sec = 1/cos).