Pronunciation (US) IPA (key): /ˌmɪl.jəˈnɛɚ/ (UK) IPA (key): /ˌmɪl.i.əˈnɛə(r)/ Audio (UK)(file) Noun Singular millionaire Plural millionaires (countable) A millionaire is a person who has one million dollars or more. The CEO was named as one of the youngest millionaires of the United States. Related words billionaire Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads