Tan"gent , a. [L. tangens, - entis, p.
pr.]
Touching; touching at a
single point; specifically (Geom.) meeting a curve or surface at a
point and having at that point the same direction as the curve or
surface; -- said of a straight
line, curve, or surface; as, a line tangent to a curve; a curve tangent to a surface;
tangent surfaces.
Tangent plane
(Geom.), a plane which touches a surface in a
point or line. -- Tangent scale (Gun.), a kind of breech sight for a cannon. -- Tangent screw (Mach.), an endless screw; a worm.
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.
Artificial, 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.
Hear it pronounced