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

Remarkably, the children who initially drew them together at Great Beginnings — Begnaud’s son Max and Kisner’s twins — were born just 10 days apart. — Janice Phelan, Kansas City Star, 31 July 2026

The coming-of-age series stars Annie and Connor, adopted twins raised by a single dad in New York. — Leigh Nordstrom, Footwear News, 30 July 2026

Adjective

Tuesday’s earthquake in Japan, one of the country’s deadliest in years, struck an area that was still recovering from twin earthquakes in 2016 but has also been shaped by the lessons of that trauma. — Mithil Aggarwal, NBC news, 31 July 2026

Footage released by the company shows the twin-engine jet rolling down the runway under its own power as engineers assess braking, steering, engine response and ground handling. — Aamir Khollam, Interesting Engineering, 31 July 2026

Verb

The Shanghai exhibition is twinned with a show by the same name at the Chapel of Santa Maria della Pietà, at this year’s Venice Biennale. — Joanne Shurvell, Forbes.com, 27 July 2026

Dan Armer, Chido Obi, both 18, Jacob Devaney, twins Jack and Tyler Fletcher, all 19, Ethan Williams, 20, Dan Gore, 21, and 22-year-old Toby Collyer joined Shea Lacey, Harry Amass and Jaydan Kamason, also all 19, on the pitch. — Carl Anka, New York Times, 25 July 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