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

a twin-engine airplane

b

: paired in a close or necessary relationship : matching

the company's twin goals of greater productivity and profits

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 of twin

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

All while Bhatia and the Højgaard twins prove themselves at age 24, and while Coody, Gerard and 23-year-old Japanese talent Ryo Hisatsune have gotten off to hot starts. —Brody Miller, New York Times, 23 Feb. 2026

Adding to the sense of confusion, police said that the twins frequently share clothes and use the same phone numbers and ID documents. —Chas Newkey-Burden, TheWeek, 22 Feb. 2026

Adjective

Details about Legacy 4 remain scant, but the accommodation comprises an owner’s suite, five guest cabins, a captain’s cabin, and six twin cabins for crew. —Rachel Cormack, Robb Report, 23 Feb. 2026

She is survived by sons Jelani Thurman, who played football for Ohio State University, and Jrem Jackson, as well as husband Jarvis Jackson and her twin sister, Kim, who also played basketball alongside her. —Theresa Braine, New York Daily News, 23 Feb. 2026

Verb

The sheets come in calming neutrals like beige, sand, grey, and white, and are available in sizes twin to California king—all for 22% off. —Mariana Best, Better Homes & Gardens, 22 Feb. 2026

The arrival of the Popoola twins EJ and OJ, from Detroit, gave the Dolphins size and athleticism. —Eric Sondheimer, Los Angeles Times, 22 Feb. 2026

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