An Etymological Dictionary of Astronomy and Astrophysics

1. Geometry: A straight line that intersects a curve in two or more points.
   

2. Trigonometry: For an → acute angle of a → right triangle, the function defined as the ratio of the → hypotenuse to the adjacent side. For any angle, the function defined as the ratio of the → radius vector to the → abscissa. Abbreviation sec.

Etymology (EN): From L. secant-, stem of secans, pr.p. of secare “to cut,”
→ section.

Etymology (PE): 1) Sekanjân, agent noun from sekanjidan “to shave, cut, scape,” cognate with šekastan “to break,” → section.
2) Sekânt, loan from Fr.