# invalidate

/ˌɪnˈvæɫɪˌdeɪt/ (US) · /ɪnvˈælɪdˌeɪt/ (UK) · CEFR B2 · Verb

Source: https://englishreference.com/word/invalidate
Updated: 2026-05-18

## Definition

to show that something is not true or correct. You use this when a fact or a rule no longer works because of new information.

For teachers: to show that something is invalid or not true; to render a legal document or rule ineffective. Transitive — requires a direct object.

## Examples

- New evidence can invalidate an old theory.
- The judge invalidated the contract because one of the signers was not legally competent at the time.
- The discovery of a significant error in the original data invalidated the entire study, forcing the researchers to begin the experiment from scratch with a larger sample size.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.