validity [vəˈlɪd.ə.ɾi] noun4 •The state of being valid, authentic or genuine.As we saw, there are strong suggestions in Marx's works that truth should be understood as meaning 'validity' in relation to human needs. — 1978 •State of having legal force. •The genuinity, as distinguished from the efficacity or the regularity, of a sacrament as a result of some formal dispositions being fulfilled. •A quality of a measurement indicating the degree to which the measure reflects the underlying construct, that is, whether it measures what it purports to measure (see reliability). formsvalidities