资料来源 : Webster's Revised Unabridged Dictionary (1913)

Prolate \Pro"late\, a. [L. prolatus, used as p. p. of proferre
   to bring forth, to extend; pro + latus, p. p. See {Pro-}, and
   {Tolerate}. ]
   Stretched out; extended; especially, elongated in the
   direction of a line joining the poles; as, a prolate
   spheroid; -- opposed to {oblate}.

   {Prolate cycloid}. See the Note under {Cycloid}.

   {Prolate ellipsoid} or {spheroid} (Geom.), a figure generated
      by the revolution of an ellipse about its major axis. See
      {Ellipsoid of revolution}, under {Ellipsoid}.

资料来源 : WordNet®

prolate cycloid
     n : a cycloid generated by a point outside the rolling circle