Dictionary.net

(in the United States) the number that is represented as a one followed by 9 zeros

(in Britain) the number that is represented as a one followed by 12 zeros

the number that is represented as a one followed by 12 zeros; in the United Kingdom the usage followed in the United States is frequently seen

denoting a quantity consisting of one thousand million items or units in the United States

In the United States and France, one thousand millions (1,000,000,000); in England and Germany, a million millions (1,000,000,000,000).

A million of millions (1,000,000,000,000); or, according to the French method of numeration, one thousand millions (1,000,000,000).

A thousand millions (1,000,000,000).

A million millions (1,000,000,000,000).

n. [Latin, French] According to the French method of numeration, a thousand millions, or 1,000,000,000; according to the English method, a million of millions, or 1,000,000,000,000.