[zil-yuh n]Informal.

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

an extremely large, indeterminate number.


of, relating to, or amounting to a zillion.

Origin of zillion

First recorded in 1930–35; jocular alteration of million, billion, etc.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for zillion

Contemporary Examples of zillion

Historical Examples of zillion

  • There were about a zillion startups who were trying to make a buck on the Xnet.

    Little Brother

    Cory Doctorow

British Dictionary definitions for zillion


noun plural -lions or -lion

(often plural) an extremely large but unspecified number, quantity, or amountzillions of flies in this camp


  1. amounting to a zilliona zillion different problems
  2. (as pronoun)I found a zillion under the sink

Word Origin for zillion

C20: 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

Word Origin and History for zillion

1944, arbitrary coinage with no definite numerical value; first recorded in Damon Runyon.

Online Etymology Dictionary, © 2010 Douglas Harper