invalid

C2+ Topic:Describing Qualities

US /ɪnˈvælɪd/ UK /ɪnˈvælɪd/ See IPA manual

Meanings

1

adj
not legally or logically valid; (ˈɪnvəlɪd) a person weakened by illness

The contract was declared invalid because of a missing signature.

Thesaurus

Synonyms

1 adj · not legally or logically... void null unsound baseless illegitimate worthless fallacious

Opposites

valid sound legitimate

Word family

Derived forms invalidate invalidityinvalidlyinvalidism

Related forms valid validity

Etymology

From Latin invalidus 'weak, infirm', from in- 'not' plus validus 'strong', from valere 'to be strong'.

invalidus Latin valere Latin

View etymology graph ->

Topics

Describing Qualities

External links

# invalid

**Type:** Word
**Level:** C2+
**Part of speech:** adj
**IPA (US):** /ɪnˈvælɪd/
**IPA (UK):** /ɪnˈvælɪd/

## Meanings
1. not legally or logically valid; (ˈɪnvəlɪd) a person weakened by illness

## Examples
- The contract was declared invalid because of a missing signature.

## Synonyms
- void
- null
- unsound
- baseless
- illegitimate
- worthless
- fallacious

## Antonyms
- valid
- sound
- legitimate

## Derived Forms
- invalidate
- invalidity
- invalidly
- invalidism

## Related Forms
- valid
- validity

## Roots and Affixes
- Root: invalidus
- Root: valere

## Etymology
From Latin invalidus 'weak, infirm', from in- 'not' plus validus 'strong', from valere 'to be strong'.

## AI Etymology
Invalid comes from Latin invalidus 'weak, infirm', from in- 'not' plus validus 'strong', from valere 'to be strong'. The form is best read as a historical transfer or inheritance, with its older language material carrying the main semantic load. As an adjective and noun, it carries the sense "not legally or logically valid; (ˈɪnvəlɪd) a person weakened by illness", with the older formation still helping explain the modern use. Relevant historical forms include Latin invalidus and Latin valere. Derivative forms include invalidate, invalidity, invalidly, invalidism; related words include valid, validity.

## Topics
- Describing Qualities

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