**singleton**

Definition of singleton 

1 : a card that is the only one of its suit originally dealt to a player

2a : an individual member or thing distinct from others grouped with it

b : an offspring born singly "singletons are more common than twins"


https://www.merriam-webster.com/dictionary/singleton

further source and examples:

[https://en.oxforddictionaries.com/definition/singleton][1]

1.2 *informal* A person who is not married or in a long-term relationship.

‘At tonight's game there don't seem to be any singletons on the prowl, but there are three couples on the ice.’

‘And 1.95 million single women live in New York City - the Mecca of singletons - alone.’

‘Her job is so much fun, she said, and time-consuming, too, that she has postponed ending her days as a singleton, also fodder for the cynicism and suspicion of others.’

 ‘This totally non-profit venture will bring singletons together for a night of frivolity.’

Also, [https://www.collinsdictionary.com/dictionary/english/singleton][2]

Word forms: plural singletons
countable noun
A singleton is someone who is neither married nor in a long-term relationship.

Bank is a 38-year-old singleton who grew up in Philadelphia.


  [1]: https://en.oxforddictionaries.com/definition/singleton
  [2]: https://www.collinsdictionary.com/dictionary/english/singleton