The Collaborative International Dictionary of English v.0.48:

Bugger \Bug"ger\, n. [F. bougre, fr. LL. Bulgarus, a Bulgarian,
   and also a heretic; because the inhabitants of Bulgaria were
   infected with heresy. Those guilty of the crime of buggery
   were called heretics, because in the eyes of their
   adversaries there was nothing more heinous than heresy, and
   it was therefore thought that the origin of such a vice could
   only be owing to heretics.]
   1. One guilty of buggery or unnatural vice; a sodomite.
      [1913 Webster]

   2. A wretch; -- sometimes used humorously or in playful
      disparagement. [Low]
      [1913 Webster]

WordNet (r) 3.0 (2006):

bugger
    n 1: someone who engages in anal copulation (especially a male
         who engages in anal copulation with another male) [syn:
         sodomite, sodomist, sod, bugger]
    v 1: practice anal sex upon [syn: sodomize, sodomise,
         bugger]

Moby Thesaurus II by Grady Ward, 1.0:

182 Moby Thesaurus words for "bugger":
   Mumbo Jumbo, SOB, bad boy, ball up, bastard, beat it, bird, bitch,
   bitch up, bloke, bobble, bogey, bogeyman, boggart, bogle, bollix,
   bollix up, bonehead into it, booger, boogerman, boogeyman, botch,
   boy, buffoon, bug, bugaboo, bugbear, bugger up, bungle, cat, chap,
   character, child, clear off, clear out, cock up, cook,
   coprophiliac, creep, cripple, cutup, dawdle, de-energize,
   debilitate, depart, destroy, devil, disable, disenable, drain,
   drop a brick, duck, elf, enfant terrible, enfeeble, erotomaniac,
   exhibitionist, fag, fart, fee-faw-fum, fellate, feller, fellow,
   fetishist, flub, fool, foul up, frazzle, fuck up, funmaker, geezer,
   go away, goof, goof up, gum up, guy, hamstring, hash up, heel,
   hood, hoodlum, hooligan, hors de combat, idiot, imp, inactivate,
   incapacitate, jasper, jerk, joker, jokester, kibosh, knave, knock,
   knock out, lad, lallygag, lame, leave, little devil, little monkey,
   little rascal, lollygag, louse, louse up, maim, make tracks, man,
   masochist, masturbate, meanie, mess up, minx, mischief,
   mischief-maker, mother, muck up, narcissist, necrophiliac,
   nymphomaniac, outwear, paraphiliac, pederast, pedophiliac, pill,
   pixie, play hell with, play hob with, practical joker, prankster,
   prick, puck, puke, put, queer, queer the works, rapist,
   rapscallion, rascal, rat, ream, rogue, rowdy, ruffian, ruin,
   sabotage, sadist, satyr, scamp, scapegrace, scotophiliac, screw up,
   scum, shit, shithead, shitheel, sink, skedaddle, snafu, snarl up,
   sod, sodomist, sodomite, sodomize, spike, stinkard, stinker, stud,
   toad, tot, transvestite, tucker, turd, unfit, voyeur, wag,
   waste time, weaken, wear out, wing, wreck, zoophiliac