/ Dictionary / Index R retinitis pigmentosa: Meaning and Definition of Find definitions for: retini'tis pig•men•to'sa Pronunciation: (pig"men-tō'su, -mun-), [key] — Ophthalm. Ophthalm. degeneration of the retina manifested by night blindness and gradual loss of peripheral vision, eventually resulting in tunnel vision or total blindness. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. retinitis retinoblastoma Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language