The Collaborative International Dictionary of English v.0.48:

Shab \Shab\, n. [OE. shabbe, AS. sc?b. See Scab.]
   The itch in animals; also, a scab. [Obs. or Prov. Eng.]
   [1913 Webster]

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:

Shab \Shab\, v. t.
   To scratch; to rub. [Obs.] --Farquhar.
   [1913 Webster]