Word parts change

in- + valid

Pronunciation change

adjective
noun

Adjective change

Positive
invalid

Comparative
none

Superlative
none

  1. Something that is invalid is not valid, meaning it is not correct, appropriate, or acceptable.
    I learned that my credit card was invalid when I tried to pay for dinner with it.

Noun change

Singular
invalid

Plural
invalids

  1. Someone who is invalid is very sick, often to the point of having to stay in bed or a wheelchair all the time.
    George Chaffey's invalid wife had to use a wheelchair for the last ten years of her life

Related words change