Tangent Tan"gent, n. [L. tangens, -entis, p. pr. of tangere to touch; akin to Gr. ? having seized: cf. F. tangente. Cf. {Attain}, {Contaminate}, {Contingent}, {Entire}, {Tact}, {Taste}, {Tax}, v. t.] (Geom.) A tangent line curve, or surface; specifically, that portion of the straight line tangent to a curve that is between the point of tangency and a given line, the given line being, for example, the axis of abscissas, or a radius of a circle produced. See {Trigonometrical function}, under {Function}. [1913 Webster]

{Artificial tangent}, or {Logarithmic tangent}, the logarithm of the natural tangent of an arc.

{Natural tangent}, a decimal expressing the length of the tangent of an arc, the radius being reckoned unity.

{Tangent galvanometer} (Elec.), a form of galvanometer having a circular coil and a short needle, in which the tangent of the angle of deflection of the needle is proportional to the strength of the current.

{Tangent of an angle}, the natural tangent of the arc subtending or measuring the angle.

{Tangent of an arc}, a right line, as ta, touching the arc of a circle at one extremity a, and terminated by a line ct, passing from the center through the other extremity o. [1913 Webster]

The Collaborative International Dictionary of English. 2000.