The Collaborative International Dictionary of English v.0.48:

fertilized \fertilized\ adj.
   1. united with a male gamete to begin the development of an
      individual embryo; -- of female gametes.

   Syn: impregnated, inseminated.
        [WordNet 1.5 +PJC]

   2. made more suitable for growth of crops by addition of
      fertilizer[2]; -- of soil.

   Syn: enriched.
        [PJC]

The Collaborative International Dictionary of English v.0.48:

Fertilize \Fer"ti*lize\, v. t. [imp. & p. p. Fertilized; p.
   pr. & vb. n. Fertilizing.] [Cf. F. fertiliser.]
   1. To make fertile or enrich; to supply with nourishment for
      plants; to make fruitful or productive; as, to fertilize
      land, soil, ground, and meadows.
      [1913 Webster]

            And fertilize the field that each pretends to gain.
                                                  --Byron.
      [1913 Webster]

   2. To fecundate; as, to fertilize flower. --A. R. Wallace.
      [1913 Webster]