a person who has money, property, etc. that is worth several billion (= thousand million) dollars, pounds, euros, etc.

We interviewed the multibillionaire businessman at his Miami home.

Starting out at the age of 14 with little education, he died a multi-billionaire. 他14岁开始创业，几乎没有受过什么教育，去世时已成为亿万富翁。