/ Dictionary / Index R rosin: Meaning and Definition of Find definitions for: ros•in Pronunciation: (roz'in), [key] — colophony. —v.t. to cover or rub with rosin. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: rosin (Thesaurus) rosily Rosina Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language