The Collaborative International Dictionary of English v.0.48:

Wallop \Wal"lop\, v. t.
   1. To beat soundly; to flog; to whip. [Prov. Eng., Scot., &
      Colloq. U. S.]
      [1913 Webster]

   2. To wrap up temporarily. [Prov. Eng.]
      [1913 Webster]

   3. To throw or tumble over. [Prov. Eng.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Wallop \Wal"lop\, n.
   1. A thick piece of fat. --Halliwell.
      [1913 Webster]

   2. A blow. [Prov. Eng., Scot., & Colloq. U. S.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Wallop \Wal"lop\, v. i. [Cf. OFlem. walop a gallop; of uncertain
   origin. Cf. Gallop.]
   To move quickly, but with great effort; to gallop. [Prov.
   Eng. & Scot.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Wallop \Wal"lop\, n.
   A quick, rolling movement; a gallop. [Prov. Eng. & Scot.]
   [1913 Webster]

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):

wallop
    n 1: a forceful consequence; a strong effect; "the book had an
         important impact on my thinking"; "the book packs a wallop"
         [syn: impact, wallop]
    2: a severe blow
    v 1: hit hard; "The teacher whacked the boy" [syn: whack,
         wham, whop, wallop]
    2: defeat soundly and utterly; "We'll wallop them!"

Moby Thesaurus II by Grady Ward, 1.0:

153 Moby Thesaurus words for "wallop":
   bang, bash, baste, bastinado, bat, batter, beat, belabor, belt,
   biff, birch, blast, blunder, bonk, boot, bop, buffet, bump, cane,
   careen, career, clap, clash, clip, clobber, clout, club, clump,
   coldcock, collision, cowhide, crack, crash, cudgel, cut, dash,
   deal, deal a blow, deck, dress down, drub, falter, fetch,
   fetch a blow, flagellate, flail, flap, flax, flog, flounce,
   flounder, fustigate, give a dressing-down, give a whipping,
   give the stick, hammer, hide, hit, hit a clip, horsewhip, jab, jar,
   jolt, kick, knock, knock cold, knock down, knock out, knout, labor,
   lace, lambaste, larrup, lash, lather, lay on, leather, let have it,
   lick, lurch, maul, paddle, paste, patter, pelt, percussion,
   pistol-whip, pitch, pitch and plunge, plunge, plunk, poke, pommel,
   pound, pulverize, pummel, punch, rap, rawhide, reel, rock, roll,
   scourge, seethe, shellac, shock, slam, sledgehammer, slog, slug,
   smack, smash, smite, snap, soak, sock, spank, stagger, strap,
   strike, strike at, stripe, struggle, stumble, swat, sway, swing,
   swinge, swipe, switch, tan, thrash, thrash about, thresh, thump,
   thwack, toss, toss and tumble, toss and turn, totter, trim,
   trounce, truncheon, tumble, wallow, welt, welter, whack, whale,
   wham, whip, whop, yerk