roulette

1. A game of chance in which a small ball is made to move round rapidly on a circle divided off into numbered (usually red and black) spaces. When the ball stops, it indicates the result of a variety of wagers permitted by the game. (uncountable)
2. An instance of risk-taking, especially when the downside exceeds the upside (contrary to the game of roulette where only the wager is lost). (figuratively, uncountable)
3. A small toothed wheel used by engravers to roll over a plate in order to produce rows of dots. (countable)
4. A similar wheel used to roughen the surface of a plate, as in making alterations in a mezzotint. (countable)
5. The locus of a point on a plane curve that rolls without slipping along another fixed plane curve. (countable)
6. Any of the small incisions on a sheet of stamps, used as an alternative to perforations. (countable, uncountable)
7. A cylindrical curler for the hair. (countable, uncountable)

Plural roulettes