# a thorn in the side

idiom · CEFR C1

Source: https://englishreference.com/idiom/a-thorn-in-the-side
Updated: 2026-07-29

## Meaning

A persistent source of irritation, trouble, or difficulty.

## Examples

- The noisy neighbour was a thorn in her side for years.
- The small opposition party was a constant thorn in the side of the government, blocking bills at every turn.
- That one unresolved lawsuit remained a thorn in the side of the whole merger, resurfacing at every board meeting long after everyone had hoped it was settled.

## Origin

The image appears twice in the Bible in slightly different forms. In Numbers 33:55, God warns the Israelites that any peoples they fail to drive out of Canaan will become "thorns in your sides" — a constant, wearing hindrance. Paul later uses a related figure in 2 Corinthians 12:7, describing "a thorn in the flesh" that afflicts him and will not go away. Both draw on the same everyday misery: a thorn lodged in the body is not a mortal wound but a small, sharp, unshakeable pain that nags at every movement. That is exactly the modern sense. A thorn in the side is a person or problem that keeps causing trouble over time — never quite disastrous, never quite gone. A dogged critic, a recurring fault, a rival who will not fade can all be a thorn in the side.

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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.