[ tril-yuh n ]
/ ˈtrɪl yən /

noun, plural tril·lions, (as after a numeral) tril·lion.

a cardinal number represented in the U.S. by 1 followed by 12 zeros, and in Great Britain by 1 followed by 18 zeros.


amounting to one trillion in number.

Origin of trillion

1680–90; < French, equivalent to tr(i)- tri- + (m)illion million

Related forms

tril·lionth, noun, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for trillion

British Dictionary definitions for trillion


/ (ˈtrɪljən) /


the number represented as one followed by twelve zeros (10 12); a million million
(formerly, in Britain) the number represented as one followed by eighteen zeros (10 18); a million million million
(often plural) an exceptionally large but unspecified number


(preceded by a or a numeral)
  1. amounting to a trilliona trillion stars
  2. (as pronoun)there are three trillion

Derived Forms

trillionth, noun, adjective

Word Origin for trillion

C17: from French, on the model of million
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012