thorn

IPA/θɔːn/
KK[θˈɔrn]IPA/θɔːrn/

thorn — noun

  • thornsingular
  • thornsplural

1. a short, hard, sharp-pointed part that grows on the stem or branch of certain pl

1.nounB1
Definition

a short, hard, sharp-pointed part that grows on the stem or branch of certain plants, such as roses and blackberries, and can easily prick your skin.

Example

Mei-Lin pricked her finger on a rose thorn while arranging flowers for the dinner table.

Javier wore thick leather gloves to pull the weeds, because the old vines were covered in sharp thorns.

collocation: covered in thorns

Common collocations
  • rose thorn
  • covered in thorns
  • pull out a thorn
  • sharp thorn
  • long thorn
  • thorn pricks
Synonyms
  • prickle

    usually refers to smaller, softer pointed growths like those on a nettle or bramble

  • spine

    a technical term used for pointed growths on cacti and some other plants

  • barb

    a sharp curved point that is angled backward, making it hard to pull out once stuck

Grammar Patterns

[countable] a ~ on a [plant]

Usage Note

Frequently appears after the name of the plant it comes from, as in rose thorn, cactus thorn, or hawthorn thorn.

Common Mistakes

She touched the thorn and it was soft.
She touched the thorn and it pricked her finger.
Thorns are hard and sharply pointed, not soft.

2. a tree, bush, or shrub that produces many sharp prickles on its stems and branch

2.nounB2
Definition

a tree, bush, or shrub that produces many sharp prickles on its stems and branches, often used to form hedges or natural barriers.

Example

A thick hedge of thorns surrounded the old farm and kept the cattle from wandering off.

countable: a hedge of thorns

Fatima planted a row of flowering thorns along the driveway to create a natural barrier.

Common collocations
  • thorn hedge
  • thorn bush
  • thorn tree
  • thorn thicket
  • row of thorns
Synonyms
  • brier

    a prickly shrub, especially a wild rose bush, often used in rural contexts

  • scrub

    a general term for low, dense wild vegetation that may include thorny plants

Grammar Patterns

[countable] a ~

[compound] ~ + tree/bush/hedge

Usage Note

Often appears as part of compound plant names, such as hawthorn, blackthorn, and buckthorn, which identify specific species of thorny shrubs or trees.

Common Mistakes

The garden has a thorn.' (meaning a thorny plant)
The garden has a thorn bush.' or 'The garden has a thorn hedge.
Sense 2 refers to the whole plant, not a single prickle; use a compound or descriptive phrase to be clear.

3. a person or issue that repeatedly bothers you, creates difficulties, or prevents

3.nounB2
Definition

a person or issue that repeatedly bothers you, creates difficulties, or prevents you from making progress.

Example

The unresolved tax dispute has been a thorn in Amara's side for more than two years.

idiomatic: a thorn in [someone's] side

Kwame's loud upstairs neighbour was a thorn in his side that ruined his sleep every night.

idiomatic: a thorn in his side

Common collocations
  • thorn in my side
  • thorn in her side
  • constant thorn
  • thorn in the flesh
  • become a thorn
Synonyms
  • nuisance

    a more general, less vivid word for something annoying; lacks the image of a persistent pricking pain

  • irritant

    formal or technical term for something that causes mild but ongoing frustration

  • source of vexation

    a more formal, literary-sounding alternative

Antonyms
  • comfort

    something that brings ease and reassurance, rather than ongoing irritation

  • blessing

    an unexpected good thing, opposite in emotional impact to a thorn

Grammar Patterns

a ~ in [possessive] side

Usage Note

Almost always appears in the fixed expression a thorn in someone's side (or occasionally flesh). The noun or person that follows in represents the person experiencing the annoyance.

Common Mistakes

The loud music was a thorn on my head.
The loud music was a thorn in my side.
The correct fixed expression is 'a thorn in someone's side', not 'on one's head' or other body parts.

4. a character (þ) from an early Germanic alphabet, used in Old English and Iceland

4.nounC1
Definition

a character (þ) from an early Germanic alphabet, used in Old English and Icelandic to write the sounds now spelled as 'th' in modern English.

Example

In the Old English manuscript, the scribe used a thorn at the start of the word "the."

Bjorn learned that the Icelandic word for 'you' still begins with the letter thorn, written as 'þú'.

modern usage: still used in Icelandic

Common collocations
  • letter thorn
  • thorn symbol
  • thorn represents
  • Old English thorn
  • Icelandic thorn
  • þ (thorn)
Synonyms
  • þ

    the graphic symbol itself, identical to the letter thorn

  • rune

    a broader category of early Germanic writing symbols, though thorn is technically a letter adapted from the runic alphabet

Grammar Patterns

the letter ~

~ represents [sound]

Usage Note

Distinguish from the letter eth (Ð, ð), which also represented /θ/ and /ð/ in Old English. Thorn was used at the beginning and end of words, while eth appeared in the middle. In modern Icelandic, thorn (þ) is still part of the alphabet.

Common Mistakes

The word 'then' was spelled with a thorn in Old English.' (when the sound is correct but the position is wrong)
The word 'thorn' itself began with a thorn (þ) in Old English.
The letter was used for both /θ/ and /ð/ sounds, but the letter's name gives a clear example of its own initial sound.

Word family

  • thorny
    adjectiveB2
  • thornless
    adjectiveC1
  • thornbush
    nounB2
  • thorn hedge
    noun phraseB2
  • hawthorn
    nounB2
  • blackthorn
    nounC1
  • thorny issue
    noun phraseC1

Synonym discussion

Sense: noun/1

All four words describe pointed projections on plants, but they differ in structure and technical use. A thorn is a modified stem that grows from the woody tissue of a branch—rose 'thorns' are technically prickles, but everyday English calls them thorns regardless. A prickle is a small, surface-level outgrowth of the bark or skin that can be easily rubbed off (nettle stings are caused by prickles). A spine is a modified leaf or leaf part, typical of cacti and agave plants; it is often stiffer than a prickle and remains attached. A barb is a curved point angled backward, designed to hook onto whatever touches it—think of the barbs on a blackberry vine. A spike is not strictly a plant-growth term but a general word for a long, sharp object; in botany it may refer to a pointed inflorescence rather than a defensive structure. In practice, gardeners say 'rose thorn' and 'cactus spine,' while botanists distinguish them by their origin in the plant's anatomy.

pricklespine ↗barb ↗spike ↗

Common collocations

Nouns

Adverbs

Phrases

  • thorn in the flesh
  • crown of thorns
  • thorn hedge

Prepositions

Etymology

Proto-Indo-EuropeanProto-GermanicOld EnglishEnglish

The word thorn comes from Old English þorn, which meant both the sharp plant part and the runic letter þ. It traces back to Proto-Germanic *þurnuz, and further to the Proto-Indo-European root *tr̤nós, meaning 'something sharp.' Related words exist in many Germanic languages: German has Dorn, Dutch has doorn, and Old Norse had þorn. The runic letter was named after the plant because the shape of the character looked like a thorn branch to the early Germanic peoples who carved it into wood and stone.