/ Dictionary / Index T twinning: Meaning and Definition of Find definitions for: twin•ning Pronunciation: (twin'ing), [key] — n. the bearing of two children at one birth. the coupling of two persons or things; union. the union of crystals to form a twin. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: twinning (Thesaurus) twinned twin room Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language