trillion Meaning, Definition & Usage

  1. noun a very large indefinite number (usually hyperbole)
    billion; million; jillion; gazillion; zillion.
    • there were millions of flies
  2. noun the number that is represented as a one followed by 18 zeros
    one million million million.
    • in England they call a quintillion a trillion
  3. noun the number that is represented as a one followed by 12 zeros
    one million million; 1000000000000.
    • in England they call a trillion a billion
  4. adjective satellite one quintillion in Great Britain
  5. adjective satellite one million million in the United States

WordNet

Tril"lion noun
Etymology
F. trillion, formed from the pref. tri- in imitation of million a million. Cf. Billion.
Definitions
  1. 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.

Webster 1913