in‧va‧lid‧it‧y AC /ˌɪnvəˈlɪdəti, ˌɪnvəˈlɪdɪti/ noun [uncountable] formal
[Word Family: verb: validate ≠ invalidate; noun: validity ≠ invalidity; adjective: valid ≠ invalid]

1. the state of being too ill, old, or injured to work:
invalidity benefit

2. the state of being not legally or officially acceptable

[TahlilGaran] Dictionary of Contemporary English ▲