- a cardinal number represented in the U.S. by 1 followed by 18 zeros, and in Great Britain by 1 followed by 30 zeros.
- amounting to one quintillion in number.
Origin of quintillion
1665–75; < Latin quīnt(us) fifth + -illion (as in million)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- (in Britain, France, and Germany) the number represented as one followed by 30 zeros (10 30)US and Canadian word: nonillion
- (in the US and Canada) the number represented as one followed by 18 zeros (10 18)Former Brit word: trillion
C17: from Latin quintus fifth + -illion, as in 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
Word Origin and History for quintillionth
Online Etymology Dictionary, © 2010 Douglas Harper