From Academic Kids

Generally, a singleton is something which exists alone in some way. The word is used in several different areas:

  • In mathematics, a singleton is a set with exactly one element. See singleton (mathematics).
  • In computer programming, a singleton is a common design pattern. It refers to a class which is meant to be instantiated once, and only once. It is much like a global variable in functional programming, but a "global class-instance" instead. See Singleton pattern. A singleton is also a variable that is only used once in a program, usually indicating a programming mistake. See singleton variable.
  • In variable-width encoding schemes for computer character sets, a singleton is a character encoded with one unit, as opposed to characters encoded with multiple-unit sequences.
  • In Unicode, a singleton is a character the decomposition of which consists of a single character (e.g. the "ohm sign" (Ω) is decomposed as the "Greek capital letter omega" (Ω)).
  • A singleton is a baby that is not a twin or other multiple birth.
  • In the wake of the popularity of the novel and movie Bridget Jones's Diary, the word has also become popular as a (self-)description of individuals without romantic partners, particularly applied to 20/30-something females. There is an undertone to this use of ignoring societal pressures towards partnerships.
  • In trick-taking games where suit is important, such as contract bridge and Hearts, if a hand contains only one card of a particular suit, that card is called a singleton. Certain bidding systems (notably Acol) add notional value to the hand for a short suit of this type since it exposes the possibility of trumping. Similarly, holding a "singleton Queen" (of Spades) in Hearts is a very disadvantageous position.
  • In Whisky singleton describes the last cask or charge of a Whisky.
  • In espionage a singleton is an an intelligence officer who works alone, in that he has no network.
  • In science-fiction stories involving multiple parallel realities, a singleton is a person, place, or thing that exists in only one reality, regardless of how alike said realities might be otherwise. This is often used as a rationale for travel between those worlds.
  • Singleton is the title of a short story by Greg Egan

Places called Singleton

In Australia:

In the United Kingdom:


Academic Kids Menu

  • Art and Cultures
    • Art (
    • Architecture (
    • Cultures (
    • Music (
    • Musical Instruments (
  • Biographies (
  • Clipart (
  • Geography (
    • Countries of the World (
    • Maps (
    • Flags (
    • Continents (
  • History (
    • Ancient Civilizations (
    • Industrial Revolution (
    • Middle Ages (
    • Prehistory (
    • Renaissance (
    • Timelines (
    • United States (
    • Wars (
    • World History (
  • Human Body (
  • Mathematics (
  • Reference (
  • Science (
    • Animals (
    • Aviation (
    • Dinosaurs (
    • Earth (
    • Inventions (
    • Physical Science (
    • Plants (
    • Scientists (
  • Social Studies (
    • Anthropology (
    • Economics (
    • Government (
    • Religion (
    • Holidays (
  • Space and Astronomy
    • Solar System (
    • Planets (
  • Sports (
  • Timelines (
  • Weather (
  • US States (


  • Home Page (
  • Contact Us (

  • Clip Art (
Personal tools