The Collaborative International Dictionary of English v.0.48:

Tangent \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.
   [1913 Webster]

   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.
      [1913 Webster]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

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]

WordNet (r) 3.0 (2006):

tangent
    n 1: a straight line or plane that touches a curve or curved
         surface at a point but does not intersect it at that point
    2: ratio of the opposite to the adjacent side of a right-angled
       triangle [syn: tangent, tan]

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "tangent":
   abutter, adjoiner, air line, approach, asymptote, axis, beeline,
   borderer, bottleneck, bystander, chord, collision course,
   concentralization, concentration, concourse, concurrence,
   confluence, conflux, congress, convergence, converging, crossing,
   diagonal, diameter, direct line, directrix, edge, focalization,
   focus, funnel, great-circle course, hub, immediate neighbor,
   looker-on, meeting, mutual approach, narrowing gap, neighbor,
   neighborer, normal, onlooker, perpendicular, radius, radius vector,
   right line, secant, segment, shortcut, side, spokes, straight,
   straight course, straight line, straight stretch, straightaway,
   streamline, transversal, vector



U.S. Gazetteer Places (2000):

Tangent, OR -- U.S. city in Oregon
   Population (2000):    933
   Housing Units (2000): 366
   Land area (2000):     3.778661 sq. miles (9.786686 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    3.778661 sq. miles (9.786686 sq. km)
   FIPS code:            72600
   Located within:       Oregon (OR), FIPS 41
   Location:             44.550063 N, 123.109110 W
   ZIP Codes (1990):     97389
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Tangent, OR
    Tangent