invalid: Meaning and Definition of

in•va•lid

1. an infirm or sickly person.
2. a person who is too sick or weak to care for himself or herself: My father was an invalid the last ten years of his life.
3. a member of the armed forces disabled for active service.

1. unable to care for oneself due to infirmity or disability: his invalid sister.
2. of or for invalids: invalid diets.
3. (of things) in poor or weakened condition: the invalid state of his rocking chair.

1. to affect with disease; make an invalid: He was invalided for life.
2. to remove from or classify as not able to perform active service, as an invalid.
3. to remove or evacuate (military personnel) from an active theater of operations because of injury or illness.

in•val•id

1. not valid; without force or foundation; indefensible.
2. deficient in substance or cogency; weak.
3. void or without legal force, as a contract.