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 spiny 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 of thorn

• 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

The veteran forward has long been a thorn in their side, and has a long history of trying to injure Warriors, and succeeding at it. —Joseph Dycus, Mercury News, 16 Apr. 2026

Historically, West Palm Beach’s Keiser University has been a thorn in STU’s side as the Seahawks are 8-0 all-time against the Bobcats. —Walter Villa, Miami Herald, 16 Apr. 2026

Let go of a thorn in your side as the sun meets Chiron. —Usa Today, USA Today, 16 Apr. 2026

Meanwhile, Israel’s continued attacks on Lebanon, which have killed more than 2,000 people since March 2, and Gaza could also be a thorn in negotiations, as Iran previously insisted that any cease-fire apply to the rest of the region. —Miranda Jeyaretnam, Time, 15 Apr. 2026

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