Source : Webster's Revised Unabridged Dictionary (1913)

Polyembryony \Pol`y*em"bry*o*ny\, n. [See {Poly-}, and
   {Embryo}.] (Bot.)
   The production of two or more embryos in one seed, due either
   to the existence and fertilization of more than one embryonic
   sac or to the origination of embryos outside of the embryonic
   sac.