Synonyms for Invalid:

adj.

absurd (adjective)
absurd, anachronistic, bizarre, contradictory, crazy, eccentric, fallacious, farcical, foolish, idiotic, illogical, implausible, impossible, inane, incongruous, inconsistent, irrational, ludicrous, meaningless, nonsensical, outlandish, paradoxical, preposterous, ridiculous, self-contradictory, senseless, silly.
bad (adjective)
arrant, bad, baneful, black, defective, detrimental, displeasing, faulty, inadequate, inadvisable, inferior, irremediable, poor, unfavorable, unpleasant, unsatisfactory, unsound, vile, wretched, wrong, ill-suited.
sickly (adjective)
disabled.
worthless; unfounded (adjective)
bad, fallacious, false, illogical, irrational, null, sophistic, unreasonable, unsound, void, wrong, null and void.

n.

accessible, ataxia, disability, disabled, disablement, dumb, Challenged, Developmental Disability, the blind. active, asynchronous, compatibility, compatible, correct, true, clickable, Antivirus, backward-compatible, best-of-breed, bursty, case-sensitive. amnesiac, anorexic, asthmatic, case, consumptive, depressive, diabetic, agoraphobe, bed-blocker, the critical list. alleged, allegedly, anecdotal, apparently, doubtful, seemingly, speculative, supposed, unfounded, unsubstantiated. antitrust, civil, common-law, criminal, criminally, effective, enabling, extrajudicial, extraterritorial, forensic. fallacious (noun)
indefensible, unreasonable, null and void.
invalid (noun)
bad, disable, expired, fallacious, false, handicap, incapacitate, invalidated, null, nullified, sophistic, sophistical, specious, spurious, uncollectible, unsound, void, shut in.
sick person (noun)
consumptive.

Other synonyms:

expired
expired.
Other relevant words:
case, consumptive, criminal, disable, disabled, expired, false, handicap, incapacitate, indefensible, invalidated, null, nullified, sophistic, sophistical, specious, spurious, uncollectible, unfounded, unreasonable, void, shut in, null and void.

Usage examples for invalid

  1. Still from what little he did see of the invalid it was a relief when, four years later, an accident took him away. – Our Nervous Friends Illustrating the Mastery of Nervousness by Robert S. Carroll
  2. My impression is that she is not exactly the person for the invalid room. – Harriet Martineau by Florence Fenwick Miller
  3. " He was an invalid – The Complete Project Gutenberg Works of George Meredith by George Meredith