Noun | 1. | singleton - a single object (as distinguished from a pair) |
2. | singleton - a set containing a single member set - a group of things of the same kind that belong together and are so used; "a set of books"; "a set of golf clubs"; "a set of teeth" | |
3. | singleton - the playing card that is the only card in a suit held in a bridge hand as initially dealt playing card - one of a pack of cards that are used to play card games |