The Collaborative International Dictionary of English v.0.48:

Drudge \Drudge\ (dr[u^]j), v. i. [imp. & p. p. Drudged
   (dr[u^]jd); p. pr. & vb. n. Drudging.] [OE. druggen; prob
   not akin to E. drag, v. t., but fr. Celtic; cf. Ir. drugaire
   a slave or drudge.]
   To perform menial work; to labor in mean or unpleasant
   offices with toil and fatigue.
   [1913 Webster]

         He gradually rose in the estimation of the booksellers
         for whom he drudged.                     --Macaulay.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Drudge \Drudge\, v. t.
   To consume laboriously; -- with away.
   [1913 Webster]

         Rise to our toils and drudge away the day. --Otway.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Drudge \Drudge\, n.
   One who drudges; one who works hard in servile employment; a
   menial servant. --Milton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

drudge
    n 1: one who works hard at boring tasks [syn: hack, drudge,
         hacker]
    2: a laborer who is obliged to do menial work [syn: drudge,
       peon, navvy, galley slave]
    v 1: work hard; "She was digging away at her math homework";
         "Lexicographers drudge all day long" [syn: labor,
         labour, toil, fag, travail, grind, drudge,
         dig, moil]

Moby Thesaurus II by Grady Ward, 1.0:

77 Moby Thesaurus words for "drudge":
   administer to, attend, attend on, be busy, beast of burden,
   care for, chore, dance attendance upon, dig, do for, do service to,
   domestic, domestic servant, donkeywork, dray horse, drudgery, fag,
   galley slave, greasy grind, grind, grub, grubber, hack, hammer,
   hammer away, help, hireling, keep doggedly at, labor, lackey,
   look after, maid, menial, mercenary, minister to, moil, muck,
   pander to, peg, peg away, peon, plod, plodder, plow, plug,
   plug along, plug at, plug away, plugging, pound, pound away,
   scullion, servant, serve, servitor, slave, slavery, slavey, slog,
   slog away, slogger, swot, take care of, tend, toil, toiler,
   travail, turnspit, upon, valet, wade through, wait, wait on, work,
   work away, work for, workhorse