twin

1 of 3

noun

ˈtwin 

1

a

: either of two offspring produced in the same pregnancy

b

Twins plural : gemini

2

: one of two persons or things closely related to or resembling each other

3

: a compound crystal composed of two adjoining crystals or parts of crystals of the same kind that share a common plane of atoms

twinship

ˈtwin-ˌship 

noun

twin

2 of 3

adjective

1

: born with one other or as a pair at one birth

my twin brother

twin girls

2

a

: made up of two similar, related, or connected members or parts : double

b

: paired in a close or necessary relationship : matching

c

: having or consisting of two identical units

d

: being one of a pair

twin

3 of 3

verb

twinned; twinning

transitive verb

1

: to bring together in close association : couple

2

: duplicate, match

intransitive verb

1

: to bring forth twins

2

of a crystal : to grow in a compound form with two adjoining sections that share a common plane of atoms

Synonyms

Noun

• half

Adjective

• dual
• binary

Examples of twin in a Sentence

Noun

She's the mother of twins.

The twins went swimming after lunch.

My sister just had twins.

Sarah and her brother are twins.

Adjective

the twin goals of reducing oil dependence and protecting the environment

Recent Examples on the Web

Noun

Miami — where the twins grew up and where their mother lives — made a heavy push to keep them home, and was considered a front-runner at various points in their recruitment. —Brendan Marks, New York Times, 9 July 2025

The researchers are continuing to follow the twins through age three to better understand how sleep and crying evolve in early childhood. —Daniella Gray, MSNBC Newsweek, 8 July 2025

Adjective

The line is rooted in outerwear, which includes wrap coats in twin layers of double-faced wool; reversible jackets with one side plain, the other patterned; and crinkled unisex trenchcoats that pack up neatly into a travel pouch, printed with a bicycle pattern drawn from Veldkamp’s art. —Joelle Diderich, Footwear News, 10 July 2025

Austin Metcalf was stabbed in the heart and died in the arms of his twin brother, his father, Jeff Metcalf, previously told the Star-Telegram. —Fort Worth Star-Telegram, 10 July 2025

Verb

Ami and Justin McClure are also parents to twin sisters Ava and Alexis, 12, who star in their videos alongside their younger son, Jersey, 7. Episode 4 of Born to Be Viral explores how creators can boost their viewership by making videos that follow a trending format. —Zoey Lyttle, People.com, 11 July 2025

There are also experiences with characters like Astrid and Stormfly, and twins Ruffnut and Tuffnut, all of whom are ready for interactions not just with guests but among each other. —Abbey White, HollywoodReporter, 30 May 2025

Word History

Etymology

Noun

Middle English, from twin twofold

Adjective

Middle English, twofold, double, from Old English twinn; akin to Old Norse tvinnr two by two, Old English twā two

First Known Use

Noun

14th century, in the meaning defined at sense 1a

Adjective

1593, in the meaning defined at sense 1

Verb

14th century, in the meaning defined at transitive sense 1

Phrases Containing twin

• conjoined twin
• fraternal twin
• identical twin
• Siamese twin
• twin bed
• twin-bedded
• twin bill
• twin double
• twin primes
• twin-size
• twin town
• twin-turbo

Rhymes for twin

• been
• bin
• chin
• din
• djinn
• fin
• finn
• gin
• grin
• in
• kin
• linn

Kids Definition

twin

1 of 3 adjective

ˈtwin 

1

: born with one other or as a pair at one birth

my twin brother

twin girls

2

a

: made up of two similar, related, or connected members or parts

b

: being one of a pair

a twin city

twin

2 of 3 verb

twinned; twinning

: to produce or give birth to twins

twin

3 of 3 noun

: either of two offspring produced at a birth compare fraternal twin, identical twin

Medical Definition

twin

1 of 2 adjective

ˈtwin 

: born with one other or as a pair at one birth

a twin brother

twin girls

twin

2 of 2 noun

1

: either of two offspring produced at a birth

2

twins plural : a group of two offspring born at one birth

twinship

-ˌship 

noun