<p><strong>Noun</strong></p><ul><li>an infirm or sickly person.</li><li>a person who is too sick or weak to take care of their own needs.</li><li>Archaic. a member of the armed forces disabled for active service.</li></ul><p><strong>Adjective</strong></p><ul><li>unable to care for oneself due to infirmity or disability.</li><li>of or for invalids.</li><li>(of things) in poor or weakened condition.</li></ul><p><strong>Verb (used with object)</strong></p><ul><li>to affect with disease; make an invalid.</li><li>to remove from or classify as not able to perform active service, as an invalid.</li><li>British. to remove or evacuate (military personnel) from an active theater of operations because of injury or illness.</li></ul><p><strong>Verb (used without object)</strong></p><ul><li>Archaic. to become an invalid.</li></ul>