The Collaborative International Dictionary of English v.0.48:

Colonize \Col"o*nize\, v. t. [imp. & p. p. Colonized; p. pr. &
   vb. n. Colonizing.] [Cf. F. coloniser.]
   To plant or establish a colony or colonies in; to people with
   colonists; to migrate to and settle in. --Bacon.
   [1913 Webster]

         They that would thus colonize the stars with
         inhabitants.                             --Howell.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

colonized \colonized\ adj.
   1. inhabited by people who were born in or retain strong ties
      to another country.

   Syn: settled.
        [WordNet 1.5]

   2. politically ruled by citizens of another country.
      [PJC]

   3. having a population (of animals or plants) which moved in
      from another territory.

   Syn: colonized.
        [PJC]

WordNet (r) 3.0 (2006):

colonized
    adj 1: inhabited by colonists [syn: colonized, colonised,
           settled]