twin (tw?n)n.1. One of two offspring born at the same birth.2. One of two identical or similar people, animals, or things; a counterpart.3. twins Mineralogy Two interwoven crystals that are mirror images of each other.4. A twin bed.adj.1. Being two or one of two offspring born at the same birth: twin sisters.2. Being two or one of two identical or similar people, animals, or things: twin cities; a twin bed.3. Botany Of or relating to structures, such as flowers, that occur in pairs.4. Consisting of two identical or similar parts: a twin lamp fixture.5. Being of a size that will fit a twin bed: twin sheets.v. twinned, twin·ning, twins v.intr.1. a. To give birth to twins.b. Archaic To be one of twin offspring.2. To be paired or coupled.v.tr.1. To pair or couple.2. To provide a match or counterpart to.[Middle English, from Old English twinn, twofold; see dwo- in Indo-European roots.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.twin (tw?n) n1. (Biology) a. either of two persons or animals conceived at the same timeb. (as modifier): a twin brother. See also identical3, fraternal32. a. either of two persons or things that are identical or very similar; counterpartb. (as modifier): twin carburettors. 3. (Chemistry) Also called: macle a crystal consisting of two parts each of which has a definite orientation to the othervb, twins, twinning or twinned4. to pair or be paired together; couple5. (Medicine) (intr) to bear twins6. (Chemistry) (intr) (of a crystal) to form into a twin7. (intr) archaic to be born as a twin8. (Government, Politics & Diplomacy) (tr) a. to create a reciprocal relation between (two towns in different countries); pair (a town) with another in a different countryb. (intr) (of a town) to be paired with a town in a different country[Old English twinn; related to Old High German zwiniling twin, Old Norse tvinnr double] ?twinning nCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014twin (tw?n) n., adj., v. twinned, twin?ning. n. 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. 3. a compound crystal consisting of two or more parts or crystals definitely oriented each to the other; macle. 4. Twins, Gemini (def. 1). adj. 5. being a twin or twins: twin sisters. 6. being two persons or things closely related to or closely resembling each other. 7. being one of a pair; identical. 8. consisting of two similar parts or elements joined or connected: a twin vase. 9. Zool., Bot. occurring in pairs; didymous. 10. of the nature of a twin crystal. 11. twofold or double. v.t. 12. to bring together in close relationship; pair; couple. 13. to furnish a counterpart to; match. 14. Obs. to give birth to as twins. v.i. 15. to give birth to twins. 16. to be paired or coupled. [before 900; Middle English; Old English (ge)twinn; akin to Old Frisian tw?ne, Old Norse tvinnr double, Gothic twaihnai two each (akin to twi-, two)] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.twinPast participle: twinnedGerund: twinningImperativePresentPreteritePresent ContinuousPresent PerfectPast ContinuousPast PerfectFutureFuture PerfectFuture ContinuousPresent Perfect ContinuousFuture Perfect ContinuousPast Perfect ContinuousConditionalPast ConditionalImperativetwintwinPresentI twinyou twinhe/she/it twinswe twinyou twinthey twinPreteriteI twinnedyou twinnedhe/she/it twinnedwe twinnedyou twinnedthey twinnedPresent ContinuousI am twinningyou are twinninghe/she/it is twinningwe are twinningyou are twinningthey are twinningPresent PerfectI have twinnedyou have twinnedhe/she/it has twinnedwe have twinnedyou have twinnedthey have twinnedPast ContinuousI was twinningyou were twinninghe/she/it was twinningwe were twinningyou were twinningthey were twinningPast PerfectI had twinnedyou had twinnedhe/she/it had twinnedwe had twinnedyou had twinnedthey had twinnedFutureI will twinyou will twinhe/she/it will twinwe will twinyou will twinthey will twinFuture PerfectI will have twinnedyou will have twinnedhe/she/it will have twinnedwe will have twinnedyou will have twinnedthey will have twinnedFuture ContinuousI will be twinningyou will be twinninghe/she/it will be twinningwe will be twinningyou will be twinningthey will be twinningPresent Perfect ContinuousI have been twinningyou have been twinninghe/she/it has been twinningwe have been twinningyou have been twinningthey have been twinningFuture Perfect ContinuousI will have been twinningyou will have been twinninghe/she/it will have been twinningwe will have been twinningyou will have been twinningthey will have been twinningPast Perfect ContinuousI had been twinningyou had been twinninghe/she/it had been twinningwe had been twinningyou had been twinningthey had been twinningConditionalI would twinyou would twinhe/she/it would twinwe would twinyou would twinthey would twinPast ConditionalI would have twinnedyou would have twinnedhe/she/it would have twinnedwe would have twinnedyou would have twinnedthey would have twinnedCollins English Verb Tables © HarperCollins Publishers 2011