Definition of zillionaire
: an immeasurably wealthy person
Did You Know?
The word millionaire has been used in English to designate a person who is worth a million pounds or dollars, depending on the side of the ocean, since 1786. We borrowed the word straight from the French, whose millions, of course, were in francs. Millionaire eventually no longer sufficed, and English speakers coined billionaire in 1844. Soon afterwards came multimillionaire, followed by multibillionaire in the early 1900s. Once zillion was made up as a humorous word for an indeterminately large number (patterned on million and billion), it was only a matter of time before zillionaire came along as a humorous word for a person of seemingly immeasurable wealth. Zillion and zillionaire aren't used in the most formal of writing, but they have found their way into plenty of serious publications.
Origin and Etymology of zillionaire
zillion + -aire (as in millionaire)
First Known Use: 1946
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