/ Dictionary / Index D diphtheritic: Meaning and Definition of Find definitions for: diph•the•rit•ic Pronunciation: (dif"thu-rit'ik, dip"-), [key] — adj. Pathol. pertaining to diphtheria. affected by diphtheria. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. diphtheria diphtheroid Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language