billionaire|bɪljəˈnɛə(r)|[f.prec., after millionaire.]The possessor of property worth a billion or more of the recognized standard coin of the realm;(seenext).1861O. W. HolmesElsie V. vii,One would like to give a party now and then, if one could be a billionnaire.1865E. LottGov'ness Egypt 7The billionaire merchant Prince.