# monkey wrench

idiom

Source: https://englishreference.com/idiom/monkey-wrench
Updated: 2026-08-10

## Meaning

To introduce problems, to create unexpected trouble, to sabotage.

## Examples

- His sudden change of plans threw a monkey wrench into our day.
- The new government regulations threw a monkey wrench into our project, forcing us to delay the launch by several months.
- The unexpected resignation of the lead architect threw a significant monkey wrench into the construction timeline, leaving the entire development team scrambling for a solution.

## Origin

Already in use, and not unfamiliar among mechanics, by 1832; see discussion and references at Monkey wrench § Etymology and history.

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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.