invalid1

[in-vuh-lid; British in-vuh-leed] /ˈɪn və lɪd; British ˈɪn vəˌlid/
noun
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.
Archaic. a member of the armed forces disabled for active service.
adjective
4.
unable to care for oneself due to infirmity or disability:
his invalid sister.
5.
of or for invalids:
invalid diets.
6.
(of things) in poor or weakened condition:
the invalid state of his rocking chair.
verb (used with object)
7.
to affect with disease; make an invalid:
He was invalided for life.
8.
to remove from or classify as not able to perform active service, as an invalid.
9.
British. to remove or evacuate (military personnel) from an active theater of operations because of injury or illness.
verb (used without object), Archaic.
10.
to become an invalid.
Origin
1635-45; < French invalide < Latin invalidus weak. See in-3, valid

invalid2

[in-val-id] /ɪnˈvæl ɪd/
adjective
1.
not valid; without force or foundation; indefensible.
2.
deficient in substance or cogency; weak.
3.
void or without legal force, as a contract.
Origin
1625-35; < Medieval Latin invalidus, Latin: weak; see invalid1
Related forms
invalidly, adverb
invalidness, noun
Examples from the web for invalid
  • It causes us to move from our incorrect understanding to utterly invalid conclusions.
  • The patents were declared invalid by a federal judge.
  • He had been much of an invalid, but he never lost for long his courage or his buoyancy.
  • Indeed this invalid concept of inertial frames proves both the loss of simultaneity and the negation of it.
  • Her yellow fever vaccination card had been stamped by rebel health authorities, and so was invalid, the officials tut-tutted.
  • The difference in light intensity makes that an invalid comparison.
  • The argument is invalid, the conclusion does not follow from the premises.
  • They argue that the patent is invalid because it restricts free speech and free thought.
  • Over the next few years she progressively got worse and became a total invalid, needing a wheelchair to move around in the house.
  • OK, so you are going to claim that my conclusions are invalid without actually doing any research yourself.
British Dictionary definitions for invalid

invalid1

/ˈɪnvəˌliːd; -lɪd/
noun
1.
  1. a person suffering from disablement or chronic ill health
  2. (as modifier): an invalid chair
adjective
2.
suffering from or disabled by injury, sickness, etc
verb (transitive)
3.
to cause to become an invalid; disable
4.
(usually foll by out; often passive) (mainly Brit) to require (a member of the armed forces) to retire from active service through wounds or illness
Derived Forms
invalidity, noun
Usage note
It is best to avoid using the term invalid when referring to people with chronic illnesses or disabilities
Word Origin
C17: from Latin invalidus infirm, from in-1 + validus strong

invalid2

/ɪnˈvælɪd/
adjective
1.
not valid; having no cogency or legal force
2.
(logic) (of an argument) having a conclusion that does not follow from the premises: it may be false when the premises are all true; not valid
Derived Forms
invalidity (ˌɪnvəˈlɪdɪtɪ), invalidness, noun
invalidly, adverb
Word Origin
C16: from Medieval Latin invalidus without legal force; see invalid1
Word Origin and History for invalid
adj.

"not strong, infirm," 1640s, from Latin invalidus "not strong, infirm, weak, feeble," from in- "not" (see in- (1)) + validus "strong" (see valid). Specific meaning "infirm from sickness, disease, or injury" is from 1640s.

"of no legal force," 1630s, from special use of Latin invalidus (see invalid (adj.1)).

n.

1709, originally of disabled military men, from invalid (adj.1). Invalides is short for French Hôtel des Invalides, home for old and disabled soldiers in the 7th arrondissement of Paris.

invalid in Medicine

invalid in·va·lid1 (ĭn'və-lĭd)
n.
One who is incapacitated by a chronic illness or disability. adj.
Incapacitated by illness or injury.