Trillion

According to the French notation, which is used upon the Continent generally and in the United States, the number expressed by a unit with twelve ciphers annexed; a million millions; according to the English notation, the number produced by involving a million to the third power, or the number represented by a unit with eighteen ciphers annexed. See the Note under Numeration.

the number that is represented as a one followed by 12 zeros; "in England they call a trillion a billion"

the number that is represented as a one followed by 18 zeros in the UK; "in England they call a quintillion a ‘trillion’"