The Collaborative International Dictionary of English v.0.48:

Slouch \Slouch\, v. i. [imp. & p. p. Slouched; p. pr. & vb. n.
   Slouching.]
   1. To droop, as the head.
      [1913 Webster]

   2. To walk in a clumsy, lazy manner. [Colloq.]
      [1913 Webster]