# thorn

/ˈθɔɹn/ (US) · /θˈɔːn/ (UK)

Source: https://englishreference.com/word/thorn
Updated: 2026-08-15

## Senses

### 1. sharp plant part

noun · CEFR B2

a sharp, pointed part that grows on the stem of a plant, like a rose.

For teachers: a sharp-pointed woody projection on the stem or leaf of a plant, technically a modified branch or leaf.

- Be careful when you pick the roses because they have sharp thorns.
- The desert shrubs have evolved long thorns to protect their water-rich stems from hungry animals.

### 3. a source of trouble

noun · CEFR B2

a person or thing that causes constant problems or annoyance.

For teachers: a persistent source of irritation, annoyance, or difficulty; frequently used in the idiom 'a thorn in one's side'.

- The new tax law has been a thorn in the side of small business owners.
- The investigative journalist remained a constant thorn in the administration's side, regularly exposing corruption in the local government.

### 4. the letter Þ

noun · CEFR C2 · Technical

an old letter used in English long ago, and still used in Icelandic, to make the 'th' sound.

For teachers: a character (Þ, þ) used in Old English and modern Icelandic to represent dental fricatives.

- In Old English manuscripts, you will often see the letter thorn instead of 'th'.
- Linguists note that the letter thorn was eventually replaced by the 'th' digraph in Middle English due to the influence of continental scribes.

## Examples

- I pricked my finger on a sharp thorn while picking roses.
- The thick bushes were covered in long thorns, making it impossible for us to walk through the garden.
- The poet used the image of a single thorn to represent the hidden pain within an otherwise beautiful relationship.

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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.