DuckCorp Dico

Found one definition

1.                 From 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]