thorn

noun

ˈthȯrn 

often attributive

1

a

: a sharp rigid process on a plant

especially : one that is a short, indurated, sharp-pointed, and leafless modified stem compare prickle, spine

b

: any of various sharp spinose structures on an animal

2

: a woody plant bearing sharp impeding processes (such as prickles or spines)

especially : hawthorn

3

: something that causes distress or irritation

—often used in the phrase thorn in one's side

4

: the runic letter þ used in Old English and Middle English to represent either of the fricatives \th\ or \t͟h\ and in Icelandic to represent \th\

thorned

ˈthȯrnd 

adjective

thornless

ˈthȯrn-ləs 

adjective

thornlike

ˈthȯrn-ˌlīk 

adjective

Synonyms

• headache
• nuisance
• irritant
• frustration
• rub

Examples of thorn in a Sentence

your constant questions are a thorn in my side

Recent Examples on the Web

Nearly ten months later, that tycoon Jimmy Lai – a pro-democracy firebrand and persistent thorn in Beijing’s side – remains behind bars. —Nectar Gan, CNN Money, 13 Aug. 2025

Turnover remains a thorn in the retail industry’s side. —Michael Spataro, Forbes.com, 11 Aug. 2025

Massie was such a perpetual thorn in the side of the GOP that House leaders didn’t bother to whip his vote anymore. —Eric Cortellessa, Time, 7 Aug. 2025

Kentucky Congressman Thomas Massie, a fiscal conservative and frequent thorn in the side of Trump and his Republican colleagues, marched up to Emmer. —Jay O'Brien, ABC News, 22 July 2025

Word History

Etymology

Middle English, from Old English; akin to Old High German dorn thorn, Sanskrit tṛṇa grass, blade of grass

First Known Use

before the 12th century, in the meaning defined at sense 2

Phrases Containing thorn

• a thorn in the/someone's flesh/side
• Christ's-thorn
• Christ-thorn
• Jerusalem thorn
• thorn apple

Rhymes for thorn

• borne
• bourn
• bourne
• corn
• morn
• mourn
• porn
• scorn
• shorn
• sworn
• torn
• warn

Kids Definition

thorn

noun

ˈthȯ(ə)rn 

1

: a woody plant bearing sharp processes (as prickles or spines)

especially : hawthorn

2

: a sharp stiff process on a plant

especially : a stem modified into a short, stiff, and leafless sharp point

3

: something or someone that causes distress or irritation

—often used in the phrase thorn in one's side

thorned

ˈthȯ(ə)rnd 

adjective

thornless

ˈthȯ(ə)rn-ləs 

adjective