/ Dictionary / Index O ortho-toluidine: Meaning and Definition of Find definitions for: or•tho-to•lu•i•dine Pronunciation: (ôr"thō-tu-l'i-dēn", -din), [key] a light-yellow, very slightly water-soluble liquid, CHN, the ortho isomer of toluidine: used in the manufacture of dyes, saccharin, and other organic compounds, and in textile printing processes. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. orthotics orthotropic Related Content Daily Word Quiz: exemplary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language