\Hy`per*bol"ic\, Hyperbolical \Hy`per*bol"ic*al\, a.
[L. hyperbolicus, Gr. ?: cf. F. hyperbolique.]
1. (Math.) Belonging to the hyperbola; having the nature of
   the hyperbola.
2. (Rhet.) Relating to, containing, or of the nature of,
   hyperbole; exaggerating or diminishing beyond the fact;
   exceeding the truth; as, an hyperbolical expression.
   ``This hyperbolical epitaph.'' --Fuller.
{Hyperbolic functions} (Math.), certain functions which have
   relations to the hyperbola corresponding to those which
   sines, cosines, tangents, etc., have to the circle; and
   hence, called {hyperbolic sines}, {hyperbolic cosines},
   etc.
{Hyperbolic logarithm}. See {Logarithm}.
{Hyperbolic spiral} (Math.), a spiral curve, the law of which
   is, that the distance from the pole to the generating
   point varies inversely as the angle swept over by the
   radius vector.