Nonillion \No*nil"lion\, n. [L. nonus ninth + -illion, as in E.
million.]
According to the French and American notation, a thousand
octillions, or a unit with thirty ciphers annexed; according
to the English notation, a million octillions, or a unit with
fifty-four ciphers annexed. See the Note under {Numeration}.
[1913 Webster]