/ Dictionary / Index T twin-size: Meaning and Definition of Find definitions for: twin-size Pronunciation: (twin'sīz"), [key] — adj. (of a bed) approximately 39 in. (99 cm) wide and between 75 and 76 in. (191 and 193 cm) long; single. pertaining to or made for a twin-size bed:Cf. twin-size sheets. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. twin-screw twirl 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