# schoolboy error

idiom

Source: https://englishreference.com/idiom/schoolboy-error
Updated: 2026-08-10

## Meaning

A fundamental, simple mistake.

## Examples

- Forgetting to save my work was a total schoolboy error.
- The team lost the championship because the goalkeeper made a schoolboy error in the final minute.
- Despite his years of professional experience, the architect committed a schoolboy error by failing to account for the building's structural load.

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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.