'Millionaire' definitions:

Definition of 'millionaire'

From: WordNet
noun
A person whose material wealth is valued at more than a million dollars

Definition of 'Millionaire'

From: GCIDE
  • 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]

Synonyms of 'millionaire'

From: Moby Thesaurus