Invalid may refer to: *

Patient A patient is any recipient of health care services that are performed by Health professional, healthcare professionals. The patient is most often Disease, ill or Major trauma, injured and in need of therapy, treatment by a physician, nurse, op ...

, a sick person * one who is confined to home or bed because of illness,

disability Disability is the experience of any condition that makes it more difficult for a person to do certain activities or have equitable access within a given society. Disabilities may be Cognitive disability, cognitive, Developmental disability, d ...

or injury (sometimes considered a

politically incorrect "Political correctness" (adjectivally "politically correct"; commonly abbreviated to P.C.) is a term used to describe language, policies, or measures that are intended to avoid offense or disadvantage to members of particular groups in society. ...

term) *

Invalid (film) ''Invalid'' is a Slovak dark comedy directed by Jonáš Karásek on the original screenplay by Tomáš Dušička. The film, situated in the 1990s post-Communist Slovakia, tells a story of a working-class man Lacko, who becomes disabled due to bei ...

, a 2023 Slovak black comedy movie * .invalid, a top-level Internet domain not intended for real use As the opposite of valid: *

Validity (logic) In logic, specifically in deductive reasoning, an argument is valid if and only if it takes a form that makes it impossible for the premises to be truth, true and the conclusion nevertheless to be False (logic), false. It is not required for a va ...

, in logic, true premises cannot lead to a false conclusion *

Validity (statistics) Validity is the main extent to which a concept, conclusion, or measurement is well-founded and likely corresponds accurately to the real world. The word "valid" is derived from the Latin validus, meaning strong. The validity of a measurement tool ...

, a measure which is measuring what it is supposed to measure

See also