The Collaborative International Dictionary of English v.0.48:

Castellated \Cas"tel*la`ted\, a. [LL. castellatus, fr.
   castellare. See Castle.]
   1. Inclosed within a building; as, a fountain or cistern
      castellated. [Obs.] --Johnson.
      [1913 Webster]

   2. Furnished with turrets and battlements, like a castle;
      built in the style of a castle.
      [1913 Webster]

WordNet (r) 3.0 (2006):

castellated
    adj 1: having or resembling repeated square indentations like
           those in a battlement; "a crenelated molding" [syn:
           embattled, battlemented, castled, castellated]