The Collaborative International Dictionary of English v.0.48:

localise \localise\ v. t.
   Same as localize. [Chiefly Brit.]

   Syn: localize.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

localise
    v 1: identify the location or place of; "We localized the source
         of the infection" [syn: place, localize, localise]
    2: concentrate on a particular place or spot; "The infection has
       localized in the left eye" [syn: localize, localise,
       focalize, focalise]
    3: restrict something to a particular area [syn: localize,
       localise]
    4: locate; "The film is set in Africa" [syn: set, localize,
       localise, place]