The Collaborative International Dictionary of English v.0.48:

Shab \Shab\, v. t. [imp. & p. p. Shabbed; p. pr. & vb. n.
   Shabbing.] [See Scab, 3.]
   To play mean tricks; to act shabbily. [Obs. or Prov. Eng.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Shabbed \Shab"bed\, a.
   Shabby. [Obs.] --Wood.
   [1913 Webster]