[ twin ]
See synonyms for: twintwinnedtwinningtwins on

  1. either of two children or animals brought forth at a birth.

  2. either of two persons or things closely related to or closely resembling each other.

  1. Also called twin room. a type of hotel accommodation with twin beds, for occupancy by two persons.: Compare double (def. 13).

  2. Also called hemitrope. Crystallography. a compound crystal consisting of two or more parts or crystals definitely oriented each to the other; macle.

  3. Twins, Astronomy, Astrology. the constellation or sign of Gemini.

  1. being a twin or twins: twin sisters.

  2. being two persons or things closely related to or closely resembling each other.

  1. being one of a pair; identical: a twin bracelet; a twin peak.

  2. consisting of two similar parts or elements joined or connected: a twin vase.

  3. Botany, Zoology. occurring in pairs; didymous.

  4. Crystallography. of the nature of a twin; hemitrope.

  5. twofold or double.

verb (used with object),twinned, twin·ning.
  1. to bring together in close relationship; pair; couple.

  2. to furnish a counterpart to or a replica of; match.

  1. Informal. to divide or convert into two, parts, similar items, etc.: The old movie palace will be twinned, making two smaller theaters.

  2. Informal. to link or combine with: The new grocery store is twinned with a restaurant.

  3. Crystallography. to form into a twin.

  4. Obsolete. to give birth to as twins.

verb (used without object),twinned, twin·ning.
  1. to give birth to twins.

  2. to be paired or coupled.

  1. to match or resemble someone or something in a specific way, and to acknowledge this resemblance: They are twinning so hard right now.Check out these photos of moms and daughters twinning!

Origin of twin

First recorded before 900; Middle English adjective twynne, twinne, Old English adjective twinn “twofold, double”; noun and adjective getwinn “double,” (plural getwinnas “twins”); akin to Old Frisian twīna, twīne “two together,” Old Norse tvinnr “double,” Gothic twaihnái “two each”

Words that may be confused with twin

Words Nearby twin

Other definitions for twin (2 of 2)

[ twin ]

verb (used with or without object),twinned, twin·ning.Scot. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use twin in a sentence

British Dictionary definitions for twin


/ (twɪn) /

    • either of two persons or things that are identical or very similar; counterpart

    • (as modifier): twin carburettors

  1. Also called: macle a crystal consisting of two parts each of which has a definite orientation to the other

verbtwins, twinning or twinned
  1. to pair or be paired together; couple

  2. (intr) to bear twins

  1. (intr) (of a crystal) to form into a twin

  2. (intr) archaic to be born as a twin

  3. (tr)

    • to create a reciprocal relation between (two towns in different countries); pair (a town) with another in a different country

    • (intr) (of a town) to be paired with a town in a different country

Origin of twin

Old English twinn; related to Old High German zwiniling twin, Old Norse tvinnr double

Derived forms of twin

  • twinning, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for twin


[ twĭn ]

  1. One of two offspring born of a single gestation. Identical twins result from the division of a fertilized egg. Fraternal twins result from the fertilization of two separate eggs at the same time.

  2. A crystal structure consisting of two intergrown crystals that are mirror images of each other. Mineral twins can form as result of defective crystal growth in response to stress from rock deformation or during magma cooling.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.