\Hy*per"bo*loid\, n. [Hyperbola + -oid: cf. F.
hyperbolo["i]de.] (Geom.)
A surface of the second order, which is cut by certain planes
in hyperbolas; also, the solid, bounded in part by such a
surface.
{Hyperboloid of revolution}, an hyperboloid described by an
   hyperbola revolving about one of its axes. The surface has
   two separate sheets when the axis of revolution is the
   transverse axis, but only one when the axis of revolution
   is the conjugate axis of the hyperbola.

\Hy*per"bo*loid\, a. (Geom.)
Having some property that belongs to an hyperboloid or
hyperbola.