centillion

noun

cen·​til·​lion sen-ˈtil-yən 

often attributive

US : a number equal to 1 followed by 303 zeros see Table of Numbers

also, British : a number equal to 1 followed by 600 zeros see Table of Numbers

Word History

Etymology

Latin centum + English -illion (as in million)

First Known Use

1852, in the meaning defined above