Source : Webster's Revised Unabridged Dictionary (1913)

Unsaddle \Un*sad"dle\, v. t. [1st pref. un- + saddle.]
   1. To strip of a saddle; to take the saddle from, as a horse.

   2. To throw from the saddle; to unhorse.

Source : WordNet®

unsaddle
     v : remove the saddle from; "They unsaddled their mounts" [syn:
         {offsaddle}] [ant: {saddle}]