Definitions
1.noun(modern British & Australian, short scale) a thousand million (logic: 1,000 × 1,000^2): 1 followed by nine zeros, 109; a milliard
2.noun(British & Australian, long scale) A million million (logic: 1,000,000^2): a 1 followed by twelve zeros; 1012
3.nounAn unspecified very large number."There were billions of people at the concert."
4.nounInitialism of Brown lunation number.