Oxford Advanced American Dictionary

Definition of invalid adjective from the Oxford Advanced Learner's Dictionary

invalid

adjective
 
invalid pronunciation English ɪnˈvælɪd invalid pronunciation American ɪnˈvælɪd
1 not legally or officially acceptableThe treaty was declared invalid because it had not been ratified.People with invalid papers are deported to another country.2 not based on all the facts, and therefore not correctan invalid argument3 (computing) of a type that the computer cannot recognizeAn error code will be displayed if any invalid information has been entered.invalid characters
Opposite
valid