1. [n]  someone who holds property by usufruct
2. [adj]  of or relating to the nature of a usufruct

USUFRUCTUARY is a 12 letter word that starts with U.

1. \U`su*fruc"tu*a*ry\, n. [L. usufructuarius.] (Law)
   A person who has the use of property and reaps the profits of
   it. --Wharton.
   
   

2. \U`su*fruc"tu*a*ry\, a. (Law)
   Of or pertaining to a usufruct; having the nature of a
   usufruct.
   
         The ordinary graces bequeathed by Christ to his church,
         as the usufructuary property of all its members.
                                                  --Coleridge.