invalid

//ɪnˈvælɪd/, /ˈɪnvəlɪd//
B2Frequency Level 12Neutral
Visual representation of invalid

Adjective

invalidCanonical form
1

Not legally or officially acceptable; null and void.

The contract was declared invalid because it lacked a signature.

2

Not based on truth or reason; false or incorrect.

His argument was invalid because it was based on false assumptions.

3

(of a person) Suffering from illness or disability; infirm.

She spent years caring for her invalid mother.

Noun

invalidSingular
invalidsPlural
1

A person who is chronically ill or disabled and requires care.

She devoted her life to caring for her invalid mother.

Synonym

Verb

1

To remove someone from active service due to illness or injury.

The soldier was invalided out of the army after being wounded in battle.