The Collaborative International Dictionary of English v.0.48:

Trudge \Trudge\, v. i. [imp. & p. p. Trudged; p. pr. & vb. n.
   Trudging.] [Perhaps of Scand. origin, and originally
   meaning, to walk on snowshoes; cf. dial. Sw. truga, trudja, a
   snowshoe, Norw. truga, Icel. [thorn]r[=u]ga.]
   To walk or march with labor; to jog along; to move wearily.
   [1913 Webster]

         And trudged to Rome upon my naked feet.  --Dryden.
   [1913 Webster]

WordNet (r) 3.0 (2006):

trudge
    n 1: a long difficult walk
    v 1: walk heavily and firmly, as when weary, or through mud;
         "Mules plodded in a circle around a grindstone" [syn:
         slog, footslog, plod, trudge, pad, tramp]

Moby Thesaurus II by Grady Ward, 1.0:

104 Moby Thesaurus words for "trudge":
   airing, amble, andante, barge, bowl along, bundle, chug on,
   claudication, clump, constitutional, crawl, creep, dead march,
   dogtrot, drag, flounce, foot, footpace, footslog, forced march,
   funeral march, halt, hike, hippety-hop, hitch, hobble, hop, jaunt,
   jog, jog on, jog trot, jolt, jump, leisurely gait, limp, lumber,
   lumbering pace, lunge, lurch, march, mince, mincing steps, mush,
   pace, paddle, parade, peg, peripatetic journey, peripateticism,
   piaffe, piaffer, plod, plod along, plug, plug along, prance,
   promenade, rack, ramble, roll, rub on, sashay, saunter, schlep,
   scuff, scuffle, scuttle, shamble, shuffle, sidle, single-foot,
   skip, slink, slither, slog, slouch, slow march, slow motion,
   stagger, stalk, stamp, stomp, straddle, straggle, stretch, stride,
   stroll, strut, stump, swagger, swing, tittup, toddle, totter,
   traipse, tramp, trip, turn, waddle, walk, walking tour, wamble,
   wiggle, wobble