IPA: /ˈdʌbəlˌtən/
KK: /ˈdʌbəlˌtən/
A pair of cards in a card game that are the only ones of their suit in a player's hand.
In bridge, having a doubleton can be a strategic advantage during play.
Doubleton → It is formed from "double" (from Old French *dobler*, meaning to make double or twice) and "-ton" (from Old English *tun*, meaning enclosure or settlement). The word "doubleton" refers to a pair or a set of two, particularly in card games or statistics.
Think of something that is 'twice' ('double') and an 'enclosure' or 'settlement' ('-ton') — a doubleton is a set of two.