The Collaborative International Dictionary of English v.0.48:

Waddle \Wad"dle\, v. i. [imp. & p. p. Waddled; p. pr. & vb. n.
   Waddling.] [Freq. of wade; cf. AS. w[ae]dlian to beg, from
   wadan to go. See Wade.]
   To walk with short steps, swaying the body from one side to
   the other, like a duck or very fat person; to move clumsily
   and totteringly along; to toddle; to stumble; as, a child
   waddles when he begins to walk; a goose waddles. --Shak.
   [1913 Webster]

         She drawls her words, and waddles in her pace. --Young.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Waddle \Wad"dle\, v. t.
   To trample or tread down, as high grass, by walking through
   it. [R.] --Drayton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

waddle
    n 1: walking with short steps and the weight tilting from one
         foot to the other; "ducks walk with a waddle"
    v 1: walk unsteadily; "small children toddle" [syn: toddle,
         coggle, totter, dodder, paddle, waddle]

Moby Thesaurus II by Grady Ward, 1.0:

110 Moby Thesaurus words for "waddle":
   amble, andante, barge, bowl along, bundle, claudicate,
   claudication, clump, crawl, creep, dead march, dogtrot, drag,
   drag along, drag out, droop, flounce, foot, footpace, footslog,
   funeral march, gait, gallop, go dead slow, go slow, halt,
   hippety-hop, hitch, hobble, hop, idle, inch, inch along, jog,
   jog trot, jog-trot, jolt, jump, laze, leisurely gait, limp,
   lock step, lumber, lumbering pace, lunge, lurch, mince,
   mincing steps, mosey, pace, paddle, peg, piaffe, piaffer, plod,
   poke, poke along, prance, rack, roll, sashay, saunter, scuff,
   scuffle, scuttle, shamble, shuffle, shuffle along, sidle,
   single-foot, skip, slink, slither, slog, slouch, slow march,
   slow motion, slowness, stagger, stagger along, stalk, stamp, step,
   stomp, straddle, straggle, stride, stroll, strolling gait, strut,
   stump, swagger, swing, tittup, toddle, toddle along, totter,
   totter along, traipse, tread, trip, trot, trudge, velocity, walk,
   wamble, wiggle, wobble, worm, worm along