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

In 2022, his family shared that he had been rushed to the hospital because of tachycardia, a condition that makes the heart beat abnormally fast, and had been diagnosed with a congenital heart defect that is common in twins. —Clara Harter, Los Angeles Times, 21 Mar. 2026

The martial arts legend's twins, Dakota and Danilee, each posted their own tributes on Instagram, featuring photos of them with their father throughout the years. —Lori A Bashian, FOXNews.com, 21 Mar. 2026

Adjective

Judith’s twin brother, Hamnet (Ajani Cabey), hovers nearby, watching his sister’s suffering with growing alarm. —Rhoda Feng, Vulture, 23 Mar. 2026

Thus, Tommy’s sister, Ada (Sophie Rundle), and Kaulo Chiriklo (Rebecca Ferguson), the twin sister of Duke’s mother, separately implore Tommy to save his son and Gypsy people by extension. —Brian Davids, HollywoodReporter, 23 Mar. 2026

Verb

His youngest two kids, twins Dakota and Danilee, were born in 2001. —Stylecaster Editors, StyleCaster, 20 Mar. 2026

The host of the massacre is the powerful tycoon Chester Danforth (filmmaker David Cronenberg), a hotel and casino impresario, who entrusts the actual event planning to his adult children, twins Ursula and Titus (Sarah Michelle Gellar and Shawn Hatosy). —Amy Nicholson, Los Angeles Times, 19 Mar. 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