The Collaborative International Dictionary of English v.0.48:

Millionnaire \Mil`lion`naire"\, n. [F.]
   Millionaire.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Millionaire \Mil`lion*aire"\ (?; 277), n. [F. millionnaire.]
   One whose wealth is counted by millions of francs, dollars,
   or pounds; a very rich person; a person worth a million or
   more. [Written also millionnaire.]
   [1913 Webster]