Main Entry: ²tangent

Function: noun

Etymology: New Latin tangent-, tangens, from linea tangens tangent line

Date: 1594

1 a : the trigonometric function that for an acute angle is the ratio between the leg opposite to the angle when it is considered part of a right triangle and the leg adjacent b : a trigonometric function that is equal to the sine divided by the cosine for all real numbers θ for which the cosine is not equal to zero and is exactly equal to the tangent of an angle of measure θ in radians
2 : a line that is tangent; specifically : a straight line that is the limiting position of a secant of a curve through a fixed point and a variable point on the curve as the variable point approaches the fixed point
3 : an abrupt change of course : digression <the speaker went off on a tangent>
4 : a small upright flat-ended metal pin at the inner end of a clavichord key that strikes the string to produce the tone