(dated, sometimes offensive) Any person with a disability or illness.

Suffering from disability or illness. / Intended for use by an invalid.

To make invalid. Especially applied to contract law. / To make or declare (an argument, statement, or theory) unsound or erroneous; disprove.

The condition of an invalid; sickness; infirmity.

The state of being invalid; lack of validity.

(UK) The act of exempting someone from duty because of injury or ill health.

present participle of invalid

plural of invaliding

plural of invalidity

plural of invalidism