The Collaborative International Dictionary of English v.0.48:

Distend \Dis*tend"\, v. t. [imp. & p. p. Distended; p. pr. &
   vb. n. Distending.] [L. distendere, distentum, distensum;
   dis- + tendere to stretch, stretch out: cf. F. distendre to
   distend, d['e]tendre to unbend. See Tend, and cf.
   Detent.]
   1. To extend in some one direction; to lengthen out; to
      stretch. [R.]
      [1913 Webster]

            But say, what mean those colored streaks in heaven
            Distended as the brow of God appeased? --Milton.
      [1913 Webster]

   2. To stretch out or extend in all directions; to dilate; to
      enlarge, as by elasticity of parts; to inflate so as to
      produce tension; to cause to swell; as, to distend a
      bladder, the stomach, etc.
      [1913 Webster]

            The warmth distends the chinks.       --Dryden.

   Syn: To dilate; expand; enlarge; swell; inflate.
        [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

127 Moby Thesaurus words for "distended":
   adipose, bagging, baggy, ballooning, beefy, bellying, big-bellied,
   billowing, billowy, bloated, blown up, blowzy, bosomy, brawny,
   bulbose, bulbous, bulging, bumped, bumpy, bunched, bunchy, burly,
   bursting, buxom, choked, chubby, chunky, congested, corpulent,
   crammed, crowded, dilated, drenched, dropsical, dumpy, edematous,
   enchymatous, fat, fattish, filled to overflowing, flatulent,
   fleshy, full, gassy, glutted, gorged, gross, heavyset, hefty,
   hillocky, hippy, hummocky, hyperemic, imposing, in spate,
   incrassate, inflated, jam-packed, jammed, lusty, meaty, moutonnee,
   obese, overblown, overburdened, overcharged, overfed, overflowing,
   overfraught, overfreighted, overfull, overladen, overloaded,
   overstocked, overstuffed, oversupplied, overweight, overweighted,
   packed, paunchy, plethoric, plump, pneumatic, podgy, portly,
   potbellied, pouching, pudgy, puffed up, puffy, pursy,
   ready to burst, roly-poly, rotund, rounded, running over, satiated,
   saturated, soaked, square, squat, squatty, stalwart, stocky, stout,
   strapping, stuffed, stuffed up, supercharged, supersaturated,
   surcharged, surfeited, swelled, swelling, swollen, thick-bodied,
   thickset, top-heavy, tubby, tumid, turgid, ventose, verrucated,
   verrucose, warty, well-fed, windy