Synonyms for Invalid (same or very similar meaning)
WordNet sense 1 (someone who is incapacitated by a chronic illness or injury):
shut-in
WordNet sense 2 (lacking any legal or binding force):
null, void
WordNet sense 3 (erroneous and usually accidental):
false
WordNet sense 4 (containing or based on a fallacy):
fallacious, unsound
WordNet sense 5 (not capable of being collected):
bad
WordNet sense 6 (injure permanently):
disable, handicap, incapacitate
From the ODE community, based on WordNet
add/edit