legitimacyPronunciation: /lɪˈdʒɪtɪməsi/Translate legitimacy | into German | into Italian Definition of legitimacy noun [mass noun] 1conformity to the law or to rules:refusal to recognize the legitimacy of both governments (with reference to a child) the quality of being legitimate:disputes over the legitimacy of heirs 2ability to be defended with logic or justification; validity:it is difficult to judge the legitimacy of the rumourlegitimacy in other Oxford dictionaries Definition of legitimacy in the US English dictionary