[ uhn-di-sil-yuh n ]
/ ˌʌn dɪˈsɪl yən /

noun, plural un·de·cil·lions, (as after a numeral) un·de·cil·lion.

a cardinal number represented in the U.S. by 1 followed by 36 zeros, and in Great Britain by 1 followed by 66 zeros.


amounting to one undecillion in number.

Origin of undecillion

1930–35; < Latin undec(im) eleven (ūn(us) one + -decim, combining form of decem ten) + -illion, as in million

OTHER WORDS FROM undecillion

un·de·cil·lionth, adjective, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for undecillion

  • "An undecillion is ten raised to the 36th power," Freddy sighed, fearing that he wasn't getting through to Willy.

    Master of None|Lloyd Neil Goble