Emily Dickinson Lexicon

floss, n. [Poss. from OFr flosche, down, pile of velvet; cf. L. flos, flower.]

1. Down; woven filaments; soft strands of a spider web; [word play on “Flower” and “Floss”] bloom; blossom; silky substance in the husks of certain plants.
2. Fiber from a silkworm; material which forms a cocoon, enveloping the caterpillar as it becomes a butterfly; [fig.] metamorphosis.
3. Silk; fragile strand; delicate filament; fine breakable thread.