Definition of doubleton in English:



  • 1(in card games, especially bridge) a pair of cards which are the only cards of their suit in a hand.

    • ‘In a trump contract, the play of a higher card followed by a lower one may be made from a doubleton, indicating a desire to ruff, rather than just from a holding including a high card.’
    1. 1.1 A pair of people or things.
      • ‘Additionally, all singleton, doubleton, and tripleton sites (variants that appear, respectively, only once, twice, or three times in the total sample) were verified by reamplification and resequencing.’
      • ‘Of these, 75 are singletons, two are doubletons, and one is present in three sequences.’
      • ‘Initially, the differential sites are classified into singletons, doubletons, or tripletons for each of the six OTUs separately or for the various combinations of the OTUs, as described in Materials and Methods.’
      • ‘A quatraton is inferred either from the presence of two singletons, no doubletons, and no tripletons or from the presence of no singletons, one doubleton, and no tripletons.’
      • ‘We excluded singletons and doubletons and compared the following seven sites in order: M1046, M1312, M1414, M4325, A2144, A3203, and A3416.’
      • ‘The difference in sign of Tajima's D for each locus separately suggests a slight excess of singletons and doubletons in the North Carolina population, although this is not significant.’
      • ‘The distribution of singletons, doubletons (low frequency variants), and other (high frequency) variants among the continents was investigated.’
      pair, couple, duo, twosome, duology
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Early 20th century: from double, on the pattern of singleton.