/ Dictionary / Index D deficiency disease: Meaning and Definition of Find definitions for: defi'ciency disease" Pronunciation: [key] — Pathol. Pathol. any illness associated with an insufficient supply of one or more essential dietary constituents. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. deficiency account deficiency judgment Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language