singleton

Etymology

From single + -ton, probably following the model of simpleton.

noun

1. (playing cards) A playing card that is the only one of its suit in a hand, especially at bridge.
2. (playing cards) A hand containing only one card of a certain suit.
3. A single object, especially one of a group.
4. (computing) A class that may not be instantiated more than once, i.e. that implements the singleton design pattern.
5. (mathematics) A set with exactly one element.
6. A child or animal that is born singly, not as a twin or other multiple birth.
   singleton preterm birth
7. A person without a romantic partner.
8. A person without a dissociative identity.
9. (phonetics) A single consonant, as opposed to a geminated consonant.
   singleton sonorants