/ Dictionary / Index R registered dietitian: Meaning and Definition of Find definitions for: reg'istered dieti'tian Pronunciation: [key] a person who has fulfilled all the educational and examination requirements of the American Dietetic Association for recognition as a qualified nutrition specialist. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. registered bond registered mail Related Content Daily Word Quiz: reluctant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language