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

Instead, the Raytheon subsidiary concentrates on the XA-103 engine that is the main candidate to power it, and the all-digital design strategy that uses a digital twin to accelerate the engine's development compared to conventional methods. —David Szondy march 01, New Atlas, 1 Mar. 2026

This Maeve organic cotton piece looks like something Dorothy Draper would select, and comes in a wide range of sizing (from twin to California King beds) so everyone can add this bold bedding to their cart. —Yelena Moroz Alpert, Architectural Digest, 28 Feb. 2026

Adjective

The twin-engine jets can also be armed with missiles that home in on electronic transmissions like radars and communications centers. —Brad Lendon, CNN Money, 2 Mar. 2026

The River Is Waiting follows Corby, a dad laid off from his job in an advertising firm’s art department, who secretly drinks 100-proof rum and abuses prescription medication while caring for his twin 2-year-olds. —Eric Magnuson, The Atlantic, 2 Mar. 2026

Verb

After graduating from Evangelical Christian School in Cordova, twins Kylan and Niya Johnson plan to enroll at Arizona State University in the fall. —Corey Davis, Memphis Commercial Appeal, 3 Mar. 2026

The couple subsequently adopted Zahara from Ethiopia, while Shiloh and twins Vivienne and Knox are the ex-couple’s birth children. —Martha Ross, Mercury News, 27 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