DuckCorp Dico

Found one definition

1.                 From English - German Ding/FreeDict dictionary ver. 1.9-fd1:
                   
   
   
                   
                     
   rationalise /ɹˈaʃənəlˌaɪz/ <v>
    [Br.] rationalisieren <v, trans>
      Synonym: rationalize
    see: rationalizing, rationalising, rationalized, rationalised