noun

- Geometry. an intersecting line, especially one intersecting a curve at two or more points.
- Trigonometry.
- (in a right triangle) the ratio of the hypotenuse to the side adjacent to a given angle.
- (originally) a line from the center of a circle through one extremity of an arc to the tangent from the other extremity.
- the ratio of the length of this line to that of the radius of the circle; the reciprocal of the cosine of a given angle or arc. Abbreviation: sec

adjective

- cutting or intersecting, as one line or surface in relation to another.

noun

- (of an angle) a trigonometric function that in a right-angled triangle is the ratio of the length of the hypotenuse to that of the adjacent side; the reciprocal of cosineAbbreviation: sec
- a line that intersects a curve

n.1590s, from Latin secantem (nominative secans) “a cutting,” present participle of secare “to cut” (see section (n.)). First used by Danish mathematician Thomas Fincke in “Geometria Rotundi” (1583).

- A straight line or ray that intersects a curve, especially a circle, at two or more points.
- The ratio of the length of the hypotenuse in a right triangle to the side adjacent to an acute angle. The secant is the inverse of the cosine.
- The reciprocal of the abscissa of the endpoint of an arc of a unit circle centered at the origin of a Cartesian coordinate system, the arc being of length x and measured counterclockwise from the point (1, 0) if x is positive or clockwise if x is negative.
- A function of a number x, equal to the secant of an angle whose measure in radians is equal to x.