The Collaborative International Dictionary of English v.0.48:

Drub \Drub\ (dr[u^]b), v. t. [imp. & p. p. Drubbed; p. pr. &
   vb. n. Drubbing.] [Cf. Prov. E. drab to beat, Icel. & Sw.
   drabba to hit, beat, Dan. dr[ae]be to slay, and perh. OE.
   drepen to strike, kill, AS. drepan to strike, G. & D. freffen
   to hit, touch, Icel. drepa to strike, kill.]
   To beat with a stick; to thrash; to cudgel.
   [1913 Webster]

         Soundly Drubbed with a good honest cudgel.
                                                  --L'Estrange.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Drub \Drub\, n.
   A blow with a cudgel; a thump. --Addison.
   [1913 Webster]

WordNet (r) 3.0 (2006):

drub
    v 1: beat thoroughly and conclusively in a competition or fight;
         "We licked the other team on Sunday!" [syn: cream, bat,
         clobber, drub, thrash, lick]

Moby Thesaurus II by Grady Ward, 1.0:

147 Moby Thesaurus words for "drub":
   bang, bash, baste, bastinado, bat, batter, beat, beat all hollow,
   beat hollow, beating, belabor, belt, best, biff, birch, blister,
   blow, bonk, buffet, cane, castigate, chop, clip, clobber, clop,
   clout, club, clump, cowhide, crack, cudgel, cut, dash, debacle,
   defeasance, defeat, destroy, dig, dint, do in, drubbing, drumming,
   excoriate, fix, flagellate, flail, flap, flay, flog, fusillade,
   fustigate, give a whipping, give the stick, hammer, hide, hit,
   hors de combat, horsewhip, jab, knock, knout, lace, lambaste,
   larrup, lash, lather, lay on, lick, licking, maul, outclass, outdo,
   outfight, outgeneral, outmaneuver, outpoint, outrun, outsail,
   outshine, overthrow, overwhelm, paste, patter, pelt, pistol-whip,
   plunk, poke, pommel, pound, pulverize, pummel, punch, put, rap,
   rawhide, rout, ruin, scorch, score, scourge, settle, shellac,
   shellacking, skin, skin alive, slam, slash, sledgehammer, slog,
   slug, smack, smash, smear, smite, sock, spank, stamp, stomp, strap,
   stripe, stroke, swat, swing, swinge, swipe, switch, tattoo, thrash,
   thresh, thump, thwack, trample, tread, trim, triumph over, trounce,
   trouncing, truncheon, undo, vanquishment, wallop, whack, whale,
   whip, whop, worst, yerk