Source : Webster's Revised Unabridged Dictionary (1913)

Specialize \Spe"cial*ize\, v. t.
   1. To mention specially; to particularize.

   2. To apply to some specialty or limited object; to assign to
      a specific use; as, specialized knowledge.

   3. (Biol.) To supply with an organ or organs having a special
      function or functions.

Source : WordNet®

specialize
     v 1: become more special; "We specialize in dried flowers" [syn:
          {specialise}, {narrow}, {narrow down}] [ant: {diversify},
           {diversify}]
     2: be specific about; "Could you please specify your criticism
        of my paper?" [syn: {specify}, {particularize}, {particularise},
         {specialise}] [ant: {generalize}]
     3: suit to a special purpose; "specialize one's research" [syn:
         {specialise}]
     4: devote oneself to a special area of work; "She specializes
        in honey bees"; "This plumber specialized in jacuzzis"
        [syn: {specialise}]
     5: evolve so as to lead to a new species or develop in a way
        most suited to the environment [syn: {speciate}, {differentiate},
         {specialise}]