Definition of milliardaire in English:

milliardaire

Pronunciation /ˌmɪlɪəˈdɛː/

noun

rare
  • A person possessing a thousand million pounds (dollars, etc.); an immensely wealthy person.

Origin

Late 19th century; earliest use found in Francis Edgeworth (1845–1926), economist and statistician. From milliard + -aire.