Main entry: valid
Definition: well grounded in logic or truth or having legal force
Usage: a valid inference; a valid argument; a valid contract
Antonyms: invalid
Definition: having no cogency or legal force
Definition: the absence of sound
Antonyms: unsound
Definition: not sound financially
Antonyms: unsound
Definition: not in good condition; damaged or decayed
Antonyms: illegitimate
Definition: of marriages and offspring; not recognized as lawful
Antonyms: unlogical, illogical
Definition: lacking in correct logical relation
Antonyms: illegal
Definition: prohibited by law or by official or accepted rules
Main entry: valid
Definition: still legally acceptable
Usage: the license is still valid
Antonyms: expired
Definition: having come to an end or become void after passage of a period of time