Source : Webster's Revised Unabridged Dictionary (1913)

Angiosperm \An"gi*o*sperm\ (-[a^]n"j[i^]*[-o]*sp[~e]rm), n.
   [Angio- + Gr. ?, ?, seed.] (Bot.)
   A plant which has its seeds inclosed in a pericarp.

   Note: The term is restricted to exogenous plants, and applied
         to one of the two grand divisions of these species, the
         other division including gymnosperms, or those which
         have naked seeds. The oak, apple, beech, etc., are
         angiosperms, while the pines, spruce, hemlock, and the
         allied varieties, are gymnosperms.

Source : WordNet®

angiosperm
     n : plants having seeds in a closed ovary [syn: {flowering plant}]