millions and millions; vast fortune
Refers to an enormous, almost uncountable amount of money or wealth. Often used in the compound 億万長者 (おくまんちょうじゃ, billionaire/multimillionaire).
He amassed a vast fortune.
その起業家は億万長者になった。
The entrepreneur became a billionaire.
billionaire; multimillionaire; very rich person
Compound of 億 (おく, hundred million) and 万 (まん, ten thousand), literally 'hundred millions and ten thousands', implying an immense number.