# blunder

/ˈbɫəndɝ/ (US) · /blˈʌndɐ/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/blunder
Updated: 2026-05-08

## Definition

a big or careless mistake. You use this when someone does something wrong because they were not thinking or were not careful.

For teachers: a gross, stupid, or careless mistake resulting from ignorance or lack of deliberation.

## Examples

- The goalkeeper made a terrible blunder in the final minute.
- The company's decision to ignore the new market trends proved to be a costly blunder that led to bankruptcy.
- Historians often debate whether the general's choice to divide his forces was a calculated risk or a strategic blunder that doomed the entire campaign.

## Usage notes

- Often modified by adjectives like 'costly', 'tactical', or 'fatal'.

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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.