One of the mysteries of the English language finally explained.
Definition of nonillion in US English:
nonillion
noun
Originally (especially in Britain): the cardinal number equal to the ninth power of a million (1054). Now (originally US): the cardinal number equal to the tenth power of a thousand (1030).
adjective
Numbering a nonillion; (hyperbolically) a very great many, countless.
Origin
Late 17th century; earliest use found in John Locke (1632–1704), philosopher. From French nonillion the cardinal number equal to the ninth power of a million from classical Latin nōnus ninth + French -illion (in million).