The Collaborative International Dictionary of English v.0.48:

Actualize \Ac"tu*al*ize\, v. t.
   To make actual; to realize in action. [R.] --Coleridge.
   [1913 Webster]

WordNet (r) 3.0 (2006):

actualize
    v 1: make real or concrete; give reality or substance to; "our
         ideas must be substantiated into actions" [syn: realize,
         realise, actualize, actualise, substantiate]
    2: represent or describe realistically [syn: actualize,
       actualise]