The Collaborative International Dictionary of English v.0.48:

Floss \Floss\ (?; 195), n. [It. floscio flabby, soft, fr. L.
   fluxus flowing, loose, slack. See Flux, n.]
   1. (Bot.) The slender styles of the pistillate flowers of
      maize; also called silk.
      [1913 Webster]

   2. Untwisted filaments of silk, used in embroidering.
      [1913 Webster]

   3. A body feather of an ostrich. Flosses are soft, and gray
      from the female and black from the male.
      [Webster 1913 Suppl.]

   Floss silk, silk that has been twisted, and which retains
      its loose and downy character. It is much used in
      embroidery. Called also floxed silk.

   Floss thread, a kind of soft flaxen yarn or thread, used
      for embroidery; -- called also linen floss, and floss
      yarn. --McElrath.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Floss \Floss\, n. [Cf. G. floss a float.]
   1. A small stream of water. [Eng.]
      [1913 Webster]

   2. Fluid glass floating on iron in the puddling furnace,
      produced by the vitrification of oxides and earths which
      are present.
      [1913 Webster]

   Floss hole.
      (a) A hole at the back of a puddling furnace, at which the
          slags pass out.
      (b) The tap hole of a melting furnace. --Knight.
          [1913 Webster]

WordNet (r) 3.0 (2006):

floss
    n 1: a soft loosely twisted thread used in embroidery
    2: a soft thread for cleaning the spaces between the teeth [syn:
       dental floss, floss]
    v 1: use dental floss to clean; "floss your teeth after every
         meal"

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "floss":
   blubber, breeze, butter, clay, cushion, dough, down, eiderdown,
   feather bed, feathers, fleece, flue, fluff, foam, fur, fuzz, kapok,
   lint, pile, pillow, plush, pudding, puff, putty, rubber, satin,
   silk, swansdown, thistledown, velvet, wax, wool, zephyr