**Hy`per*bol"ic** (?), **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.

© Webster 1913.