I. ˈtan-jənt adjective
Etymology: Latin tangent-, tangens, present participle of tangere to touch; perhaps akin to Old English thaccian to touch gently, stroke
Date: 1594
1.
a. : meeting a curve or surface in a single point if a sufficiently small interval is considered
straight line tangent to a curve
b.
(1) : having a common tangent line at a point
tangent curves
(2) : having a common tangent plane at a point
tangent surfaces
2. : diverging from an original purpose or course : irrelevant
tangent remarks
II. 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