The Collaborative International Dictionary of English v.0.48:

Remitter \Re*mit"ter\ (-t?r), n.
   1. One who remits. Specifically:
      (a) One who pardons.
      (b) One who makes remittance.
          [1913 Webster]

   2. (Law) The sending or placing back of a person to a title
      or right he had before; the restitution of one who obtains
      possession of property under a defective title, to his
      rights under some valid title by virtue of which he might
      legally have entered into possession only by suit.
      --Bouvier.
      [1913 Webster]

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

REMITTER, estates. To be placed back in possession.
     2. When one having a right to lands is out of possession, and
afterwards the freehold is cast upon him by some defective title, and he
enters by virtue of that title, the law remits him to his ancient and more
certain right and by an equitable fiction, supposes him to have gained
possession under it. 3 Bl. Com. 190; 18 Vin. Ab. 431; 7 Com. Dig. 234.