- 1. one thousand million; 1,000,000,000:
• The group has estimated debts of £1.2 billion.2. old-fashioned a million million
* * *billion UK US /ˈbɪljən/ noun [C] (UK bn, US b, WRITTEN ABBREVIATION bil)► one thousand million: 1,000,000,000: »
a loss of £2 billion»
The banks lost billions in the crash.
Financial and business terms. 2012.