multibillionaire

multi- +‎ billionaire

multibillionaire (plural multibillionaires)

1. A person with a net worth of multiple billions, typically measured in US dollars.
   • 2007 June 16, Diane Cardwell, “A Gadfly Becomes Persona Non Grata in City Hall”, in New York Times‎:

     But it took Mayor Michael R. Bloomberg, the multibillionaire with a reputation for cool-headedness, to actually bar him, beginning in April, from City Hall news conferences.

• multimillionaire
• multizillionaire