noun, often attributive
tre·​de·​cil·​lion | \ ˌtrē-di-ˈsil-yən How to pronounce tredecillion (audio) \

Definition of tredecillion

US : a number equal to 1 followed by 42 zeros — see Table of Numbers also, British : a number equal to 1 followed by 78 zeros — see Table of Numbers

First Known Use of tredecillion

1850, in the meaning defined above

History and Etymology for tredecillion

Latin tredecim thirteen (from tres three + decem ten) + English -illion (as in million) — more at three, ten

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The first known use of tredecillion was in 1850

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Cite this Entry

“Tredecillion.” The Dictionary, Merriam-Webster Inc., Accessed 29 January 2020.

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to assert without proof or before proving

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