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English definition of “invalid”

invalid

adjective uk   /ɪnˈvæl.ɪd/ us  
An invalid document, ticket, law, etc. is not legally or officially acceptable: I'm afraid your driving licence is invalid in Eastern Europe. An invalid opinion, argument, etc. is not correct, usually because it is not logical or not based on correct information: an invalid argument
invalidly
adverb uk   /-li/ us  
(Definition of invalid adjective from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
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