/ Dictionary / Index D diagnostician: Meaning and Definition of Find definitions for: di•ag•nos•ti•cian Pronunciation: (dī"ug-no-stish'un), [key] — n. an expert in making diagnoses, esp. a medical doctor. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: diagnostician (Thesaurus) diagnosticate diagnostics Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language