from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A pair of cards that are the only ones of their suit in a hand dealt to a player.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A set containing precisely two elements.
- n. A pair of cards of the same suit, which are the only cards of that suit in a player's hand
from The Century Dictionary and Cyclopedia
- n. In whist and bridge, a two-card suit.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. (bridge) a pair of playing cards that are the only cards in their suit in the hand dealt to a player
The appearance of East's doubleton queen was a welcome sight, and all that remained was to resolve the position of the queen of clubs.
That might be a singleton or it might be from queen-10 doubleton.
When instead he felled North's doubleton ace, he could not establish the spade suit and eventually finished two down.
If declarer believed that Sementa had chosen the unorthodox lead of a low card from a doubleton, he could now have made the contract easily because he had a tenace in diamonds – the eight would force West to cover with the nine, and declarer's six would beat West's three.
Joe Grue successfully ran the jack of hearts, crossed to the ace of hearts, and led the king of spades in the hope of felling a doubleton jack in the South hand.
In case East has a doubleton honor or two honors, Cy should play dummy's ace at Trick One.
West signaled with the ten to show a doubleton, and East let dummy's king and queen win.
"By taking the ace and 'cashing' the king, she was showing a doubleton."
If the hearts had split 3-3 (or if a defender had held K-Q doubleton), South could have drawn trumps and led to the king of diamonds to take the good hearts.
There were two ways in which this might be achieved: South might have a doubleton, or he might have the singleton king.