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

Katie Jameson, of Vancouver, Canada, is the mom of 10-year-old twins Wally and Kenzie, who share an incredibly close bond. —Ronnie Li, USA Today, 8 Feb. 2026

Likely returning home to their kids, 8-year-old twins Alexander and Ella, George recently told E! —Rachel Burchfield, InStyle, 8 Feb. 2026

Adjective

Users could input codes to quickly search the data, call up content on twin slanted screens, and manipulate documents with levers. —Big Think, 9 Feb. 2026

The first images viewers saw were the introductions of the coaches and quarterbacks for each side, generals and lieutenants, twin pillars of the franchises. —CBS News, 8 Feb. 2026

Verb

The Bring It On alum made the Goat Los Angeles premiere a family affair, posing with husband Dwayne Wade and the 7-year-old—and Kaavia had fans doing a double take with an adorable twinning style moment. —Lara Walsh, InStyle, 7 Feb. 2026

The key to nailing any coordinated dressing is much like good eyebrows—they’re sisters not twins. —Alexandra Hildreth, Vogue, 2 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