The Collaborative International Dictionary of English v.0.48:

Fertilization \Fer`ti*li*za"tion\, n.
   1. The act or process of rendering fertile.
      [1913 Webster]

   2. (Biol.) The act of fecundating or impregnating animal or
      vegetable germs; esp., the process by which in flowers the
      pollen renders the ovule fertile, or an analogous process
      in flowerless plants; fecundation; impregnation.
      [1913 Webster]

   Close fertilization (Bot.), the fertilization of pistils by
      pollen derived from the stamens of the same blossom.

   Cross fertilization, fertilization by pollen from some
      other blossom. See under Cross, a.
      [1913 Webster]

WordNet (r) 3.0 (2006):

fertilization
    n 1: creation by the physical union of male and female gametes;
         of sperm and ova in an animal or pollen and ovule in a
         plant [syn: fertilization, fertilisation,
         fecundation, impregnation]
    2: making fertile as by applying fertilizer or manure [syn:
       fertilization, fertilisation, fecundation, dressing]