The Collaborative International Dictionary of English v.0.48:

Saddle \Sad"dle\, v. t. [imp. & p. p. Saddled; p. pr. & vb. n.
   Saddling.] [AS. sadelian.]
   1. To put a saddle upon; to equip (a beast) for riding.
      "saddle my horse." --Shak.
      [1913 Webster]

            Abraham rose up early, . . . and saddled his ass.
                                                  --Gen. xxii.
                                                  3.
      [1913 Webster]

   2. Hence: To fix as a charge or burden upon; to load; to
      encumber; as, to saddle a town with the expense of bridges
      and highways.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Saddled \Sad"dled\, a. (Zool.)
   Having a broad patch of color across the back, like a saddle;
   saddle-backed.
   [1913 Webster]

WordNet (r) 3.0 (2006):

saddled
    adj 1: having a saddle on or being mounted on a saddled animal;
           "saddled and spurred and ready to ride" [ant:
           unsaddled]
    2: subject to an imposed burden; "left me saddled with the
       bill"; "found himself saddled with more responsibility than
       power"