The Collaborative International Dictionary of English v.0.48:

Mortgagee \Mort`ga*gee"\, n. (Law)
   The person to whom property is mortgaged, or to whom a
   mortgage is made or given.
   [1913 Webster] Mortgageor

WordNet (r) 3.0 (2006):

mortgagee
    n 1: the person who accepts a mortgage; "the bank became our
         mortgagee when it accepted our mortgage on our new home"
         [syn: mortgagee, mortgage holder]

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "mortgagee":
   Shylock, banker, bill collector, collection agent, credit man,
   creditor, creditress, debtee, dun, dunner, godchild, goddaughter,
   godson, insuree, lender, loan officer, loan shark, loaner,
   money broker, moneylender, moneymonger, mortgage holder,
   mortgage-holder, note-holder, pawnbroker, policyholder, usurer,
   warrantee



Bouvier's Law Dictionary, Revised 6th Ed (1856):

MORTGAGEE, estates, contracts. He to whom a mortgage is made.
     2. He is entitled to the payment of the money secured to him by the
mortgage; he has the legal estate in the land mortgaged, and may recover it
in ejectment, on the other hand he cannot commit waste; 4 Watts, R. 460; he
cannot make leases to the injury of the mortgagor; and he must account for
the profits he receives out of the thing mortgaged when in possession.
Cruise, Dig. tit. 15, c. 2.