floss

UK: /ˈflɒs/ US: /flɔs, flɑs/ ,(flôs, flos)

WordReference Random House Learner's Dictionary of American English © 2025

floss /flɔs, flɑs/   n. [uncountable]

1. Textiles
   • embroidery thread of silk or cotton.
2. strong thread used to clean between the teeth.

v. 

3. Dentistry to use dental floss on (the teeth): [no object]
   to floss regularly.
   [~ + object]
   flosses her teeth.

WordReference Random House Unabridged Dictionary of American English © 2025

floss  (flôs, flos), n. 

1. Textiles the cottony fiber yielded by the silk-cotton tree.
2. Textiles silk filaments with little or no twist, used in weaving as brocade or in embroidery.
3. any silky, filamentous matter, as the silk of corn.
4. Dentistry See dental floss. 

v.i. 

5. Dentistry to use dental floss on the teeth.

v.t. 

6. Dentistry to clean (the teeth) with dental floss. Also called floss′ silk′ (for defs. 1-3).

• French floche, as in soie floche floss silk, Old French flosche down, velvet pile (of uncertain origin, originally)
• probably 1750–60

floss′er, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

floss / flɒs/ noun

1. the mass of fine silky fibres obtained from cotton and similar plants
2. any similar fine silky material, such as the hairlike styles and stigmas of maize or the fibres prepared from silkworm cocoons
3. untwisted silk thread used in embroidery, etc
4. See dental floss
5. the floss ⇒ a dance in which people twist their hips in one direction while swinging their arms in the opposite direction with the fists closed

verb

1. to clean (between one's teeth) with dental floss
2. (intransitive) to dance the floss

Etymology: 18th Century: perhaps from Old French flosche down