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1. The number that is represented as a one followed by 9 zeros
   - one thousand million, 1000000000
    
2. [Brit, archaic] The number that is represented as a one followed by 12 zeros; in the United Kingdom the usage followed is frequently seen
   - one million million [Brit], 1000000000000 [Brit]
    
3. [informal] A very large indefinite number (usually hyperbole)
   "there were billions of flies";
   - million [informal], trillion [informal], zillion [informal], jillion [N. Amer, informal], gazillion [informal], bazillion [N. Amer, informal], bajillion [informal], squillion [informal]

1. Denoting a quantity consisting of one thousand million items or units
    
2. [Brit, archaic] Denoting a quantity consisting of one million million items or units

Derived forms: billions

See also: cardinal

Type of: large indefinite amount, large indefinite quantity, large integer

Encyclopedia: Billion