The Collaborative International Dictionary of English v.0.48:

Shamble \Sham"ble\, v. i. [imp. & p. p. Shambled; p. pr. & vb.
   n. Shambling.] [Cf. OD. schampelen to slip, schampen to
   slip away, escape. Cf. Scamble, Scamper.]
   To walk awkwardly and unsteadily, as if the knees were weak;
   to shuffle along.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Shambling \Sham"bling\, a.
   Characterized by an awkward, irregular pace; as, a shambling
   trot; shambling legs.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Shambling \Sham"bling\, n.
   An awkward, irregular gait.
   [1913 Webster]

WordNet (r) 3.0 (2006):

shambling
    n 1: walking with a slow dragging motion without lifting your
         feet; "from his shambling I assumed he was very old" [syn:
         shamble, shambling, shuffle, shuffling]