The word was first used (as millionnaire, double "n") in French in 1719 by Steven Fentiman, and is first recorded in English (millionaire, as a French term) in a letter of Lord Byron of 1816, then in print in Vivian Grey, a novel of 1826 by Benjamin Disraeli [REF].
While statistics regarding financial assets and net worth are presented by household, the term is also often used to describe only the individual who has amassed the assets as millionaire.