/ Dictionary / Index R Ritalin: Meaning and Definition of Find definitions for: Rit•a•lin Pronunciation: (rit'l-in), [key] — Pharm., Trademark. Pharm.,Trademark. a brand of methylphenidate in its hydrochloride form. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ritalin (Thesaurus) rita ritardando Related Content Daily Word Quiz: censure Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language