/ Dictionary / Index R Riggs' disease: Meaning and Definition of Find definitions for: Riggs'' disease" Pronunciation: (rigz), [key] pyorrhea (def. 2). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. rigging right Related Content Daily Word Quiz: dissonant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language