WordNet (r) 3.0 (2006):

title-holder
    n 1: someone who has won first place in a competition [syn:
         champion, champ, title-holder]

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "titleholder":
   beneficiary, cestui, cestui que trust, cestui que use, deedholder,
   feoffee, feudatory, householder, laird, landlady, landlord, lord,
   master, mesne, mesne lord, mistress, owner, proprietary,
   proprietor, proprietress, proprietrix, rentier, squire