"a person worth a million dollars, pounds, francs, etc.," 1821, from French millionnaire (1762); see million. The first in America is said to have been John Jacob Astor (1763-1848).
Entries linking to millionaire
million n.
"ten hundred thousand, a thousand thousands," late 14c., milioun, from Old French million (late 13c.), from Italian millione (now milione), literally "a great thousand," augmentative of mille "thousand," from Latin mille, which is of uncertain origin. From the start often used indefinitely for "a very great number or quantity."
In the West it was used mainly by mathematicians until 16c., but India, with its love of large numbers, had names before 3c. for numbers well beyond a billion. The ancient Greeks had no name for a number greater than ten thousand, the Romans for none higher than a hundred thousand. "A million" in Latin would have been decies centena milia, literally "ten hundred thousand." Million to one as a type of "long odds" is attested from 1761. Related: Millions.
billionaire n.
"person with assets worth a billion in the standard coin of the country," 1844, American English, from billion on model of millionaire. Marked "[Rare.]" in Century Dictionary (1902). The first in the U.S. likely was John D. Rockefeller, some time after World War I.
multi-millionaire n.
also multimillionaire, "one worth many millions" (of dollars, pounds, etc.), 1858, from multi- "many times" + millionaire.