Definition

1. Adjective:

   • No longer valid or legally acceptable: Refers to something that has lost its official force, authority, or correctness.
   • Not based on sound logic or truth: Describes reasoning, arguments, or claims that are flawed or incorrect.

2. Noun:

   • A person who is chronically ill or disabled: Refers to someone who is incapacitated by a long-term sickness or injury.

3. Verb:

   • To disable or incapacitate someone through illness or injury.
   • To release someone from active service or duty due to disability.

Usage Examples

• Adjective:

  • The contract became invalid after the expiration date.
  • Your password is invalid; please try a different one.
  • The judge dismissed the case due to invalid evidence.

• Noun:

  • The hospital has a special wing for chronic invalids.
  • She has been caring for her elderly invalid mother for years.

• Verb:

  • He was invalided out of the army after losing his leg in combat. (Often used in the passive voice: "be invalided out/ home").

Advanced Usage

• "Invalid out" (phrasal verb): To discharge someone from military service or a similar duty because they are no longer fit due to injury or illness.

  • After the accident, he was invalided out of the fire department.

• "Declare invalid": To officially state that something is no longer legally acceptable or in force.

  • The court declared the election results invalid.

Variants and Related Words

• Invalidate (verb): To make something invalid; to negate or cancel.

  • The new discovery could invalidate the old theory.

• Invalidity (noun): The state of being invalid.

  • The lawyer argued for the invalidity of the will.

Synonyms

• Adjective: void, null, expired, illegitimate, faulty, unsound, false.
• Noun: patient, sufferer, convalescent, shut-in.
• Verb: disable, incapacitate, retire, discharge.

Related Phrases

• Invalid reasoning: Flawed or illogical thinking.

  • His conclusion was based on invalid reasoning.

• Invalid claim: A claim that is not legally or factually justified.

  • The insurance company rejected the invalid claim.

Notes on Usage

• The pronunciation changes depending on the part of speech. The adjective and verb are typically pronounced /ɪnˈvæl.ɪd/ (in-VAL-id). The noun is often pronounced /ˈɪn.və.lɪd/ (IN-vuh-lid), though this distinction is not always strictly observed.
• When used as a noun referring to a person, the term can sometimes be considered dated or insensitive. Terms like "person with a disability" or "patient" are often preferred in modern, respectful contexts.

Adjective

1. no longer valid
   • the license is invalid
2. having no cogency or legal force
   • invalid reasoning
   • an invalid driver's license

Noun

1. someone who is incapacitated by a chronic illness or injury

Verb

1. injure permanently
   • He was disabled in a car accident
2. force to retire, remove from active duty, as of firemen