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]

WordNet (r) 3.0 (2006):

walloping
    adj 1: (used informally) very large; "a thumping loss" [syn:
           humongous, banging, thumping, whopping,
           walloping]
    n 1: a sound defeat [syn: thrashing, walloping, debacle,
         drubbing, slaughter, trouncing, whipping]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "walloping":
   banging, bumping, colossal, dressing-down, enormous, gargantuan,
   giant, gigantic, hiding, immense, larruping, lathering, leathering,
   licking, mammoth, monster, paddling, prodigious, slapping,
   spanking, tanning, thumping, thundering, whacking, whaling,
   whopping