# Definition of singleton in US English:

## singleton

### noun

• 1A single person or thing of the kind under consideration.

‘splitting the clumps of plants into singletons’
• ‘The variation found was due mainly to unique changes in single plants (singletons).’
1. 1.1often as modifier A child or animal born singly, rather than one of a multiple birth.
‘singleton boys’
• ‘This matching is considered 99% accurate for singletons, but for twins it is reliable only at the level of the pair: which twin is admitted cannot be identified with certainty.’
• ‘Of the 322,704 live singleton births during the study period, 8,938 were linked to a motor vehicle crash during pregnancy.’
• ‘The intrauterine environment is also different in multiple pregnancy compared with singleton pregnancy.’
• ‘While the chance of a cesarean delivery is higher in twin than in singleton births, about half of women expecting twins can have a normal vaginal delivery.’
• ‘During the study, more than 900,000 live singleton births were recorded, giving an incidence of four per 1,000 live infants born with a short umbilical cord.’
2. 1.2 (in card games, especially bridge) a card that is the only one of its suit in a hand.
• ‘This card may be either a singleton or a top card or subsequently revealed card in a stack.’
• ‘If you have a singleton or void suit, you take a big risk that the declarer will find lots of cards of this suit in the talon when he exchanges, and your partner's stop in the suit might not be enough to beat the contract.’
3. 1.3Mathematics Logic A set which contains exactly one element.
• ‘The set-theorist Ernst Zermelo proposed that the number is the empty set and for each number n, the successor of n is the singleton of n, so that 1 is, 2 is, 3 is, etc.’

### Origin

Late 19th century: from single, on the pattern of simpleton.

## singleton

/ˈsiNGɡəlt(ə)n//ˈsɪŋɡəlt(ə)n/