The Collaborative International Dictionary of English v.0.48:

D'ebris \D['e]`bris"\, n. [F., fr. pref. d['e]- (L. dis) +
   briser to break, shatter; perh. of Celtic origin.]
   1. (Geol.) Broken and detached fragments, taken collectively;
      especially, fragments detached from a rock or mountain,
      and piled up at the base.
      [1913 Webster]

   2. Rubbish, especially such as results from the destruction
      of anything; remains; ruins.
      [1913 Webster]

WordNet (r) 3.0 (2006):

debris
    n 1: the remains of something that has been destroyed or broken
         up [syn: debris, dust, junk, rubble, detritus]

Moby Thesaurus II by Grady Ward, 1.0:

81 Moby Thesaurus words for "debris":
   afterglow, afterimage, alluvion, alluvium, balance, breccia, butt,
   butt end, candle ends, chaff, clamjamfry, deposit, detritus,
   diluvium, dregs, drift, dross, dust, end, fag end, filings, fossil,
   garbage, grain, granule, granulet, gravel, grit, holdover, husks,
   junk, leavings, leftovers, litter, loess, lumber, moraine,
   odds and ends, offal, offscourings, orts, parings, raff, rags,
   refuse, relics, remainder, remains, remnant, residue, residuum,
   rest, riffraff, roach, rubbish, rubble, ruins, rump, sand, sawdust,
   scourings, scrap, scraps, scree, sediment, shadow, shavings,
   shingle, shoddy, silt, sinter, straw, stubble, stump, survival,
   sweepings, trace, trash, truck, vestige, waste