His claim to ownership is invalid.
Nobody looks after the invalid.
The girl spent all her spare time to take after her invalid mother.
This ticket has passed its expiration date, and so it is now invalid.
He never fully recovered, and had to spend the rest of his life as an invalid.
someone who is incapacitated by a chronic illness or injury
force to retire, remove from active duty, as of firemen
having no cogency or legal force
no longer valid
This is an invalid assumption.
A passport that is out of date is invalid.
He had to look after his invalid brother.
He will visit an invalid.
Her grandfather is an invalid.