The phrase "multi billionaire" refers to a person who has a net worth of over one billion dollars. It means they are extremely rich and have a wealth that is multiple times greater than a billion dollars. Full definition
What they didn't account for was multi billionaire owners investing in clubs and making the money made from gate receipts basically mil and void. (justarsenal.com)
RESOLVED: Whereas the corporation has more money than it needs and since the owners unlike Warren are not multi billionaires, the board shall consider paying a meaningful annual dividend on the shares. (sec.gov)
This is how multi billionaires think and act. (justarsenal.com)