/ Dictionary / Index D diphtheria: Meaning and Definition of Find definitions for: diph•the•ri•a Pronunciation: (dif-thēr'ē-u, dip-), [key] — n. Pathol. a febrile, infectious disease caused by the bacillus Corynebacterium diphtheriae, and characterized by the formation of a false membrane in the air passages, esp. the throat. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: diphtheria (Thesaurus) diphosphoglycerate diphtheritic Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language