Source : Webster's Revised Unabridged Dictionary (1913)

Mortgage \Mort"gage\, n. [F. mort-gage; mort dead (L. mortuus) +
   gage pledge. See {Mortal}, and {Gage}.]
   1. (Law) A conveyance of property, upon condition, as
      security for the payment of a debt or the preformance of a
      duty, and to become void upon payment or performance
      according to the stipulated terms; also, the written
      instrument by which the conveyance is made.

   Note: It was called a mortgage (or dead pledge) because,
         whatever profit it might yield, it did not thereby
         redeem itself, but became lost or dead to the mortgager
         upon breach of the condition. But in equity a right of
         redemption is an inseparable incident of a mortgage
         until the mortgager is debarred by his own laches, or
         by judicial decree. --Cowell. Kent.

   2. State of being pledged; as, lands given in mortgage.

   {Chattel mortgage}. See under {Chattel}.

   {To foreclose a mortgage}. See under {Foreclose}.

   {Mortgage deed} (Law), a deed given by way of mortgage.

Source : WordNet®

mortgage deed
     n : deed embodying a mortgage