The Collaborative International Dictionary of English v.0.48:

Wallop \Wal"lop\, v. i. [imp. & p. p. Walloped; p. pr. & vb.
   n. Walloping.] [Probably fr. AS. weallan to spring up, to
   boil or bubble. [root]147. See Well, n. & v. i.]
   [1913 Webster]
   1. To boil with a continued bubbling or heaving and rolling,
      with noise. [Prov. Eng.] --Brockett.
      [1913 Webster]

   2. To move in a rolling, cumbersome manner; to waddle. [Prov.
      Eng.] --Halliwell.
      [1913 Webster]

   3. To be slatternly. [Prov. Eng.] --Halliwell.
      [1913 Webster]