Source : Webster's Revised Unabridged Dictionary (1913)

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.

            And fertilize the field that each pretends to gain.
                                                  --Byron.

   2. To fecundate; as, to fertilize flower. --A. R. Wallace.

Source : WordNet®

fertilize
     v 1: provide with fertilizers or add nutrients to; "We should
          fertilize soil if we want to grow healthy plants" [syn:
          {fertilise}, {feed}]
     2: make fertile or productive; "The course fertilized her
        imagination" [syn: {fecundate}, {fertilise}]
     3: introduce semen into (a female) [syn: {inseminate}, {fecundate},
         {fertilise}]