Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “invalid”

See all translations

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)
What is the pronunciation of invalid?
Add Cambridge dictionaries to your browser to your website

Definitions of “invalid” in other dictionaries

Word of the Day

beginner's luck

unexpected success experienced by a person who is just starting a particular activity

Word of the Day

Think long and hard; the language of decisions

by Liz Walter,
January 28, 2015
One of the best ways (perhaps the best way) to improve your English is to learn how words go together in phrases, idioms, or other patterns such as verb/noun or adjective/noun pairs (often called ‘collocations’). This blog looks at some useful phrases and collocations connected with the subject of decisions, something we

Read More 

micro pig noun

January 26, 2015
an extremely small pig, bred to be a pet Micro pigs have become popular pets recently, with famous owners including Victoria Beckham, Paris Hilton and Olympic diver, Tom Daley.

Read More