Source : Webster's Revised Unabridged Dictionary (1913)

Remount \Re*mount"\ (r?-mount"), v. t. & i.
   To mount again.

Remount \Re*mount"\, n.
   The opportunity of, or things necessary for, remounting;
   specifically, a fresh horse, with his equipments; as, to give
   one a remount.

Source : WordNet®

remount
     n : a fresh horse especially (formerly) to replace one killed or
         injured in battle
     v 1: mount again; "he remounted his horse"
     2: mount again, as after dissembling something
     3: provide with fresh horses; "remount a regiment"