/ Dictionary / Index R reflection nebula: Meaning and Definition of Find definitions for: reflec'tion neb"ula Pronunciation: [key] — Astron. Astron. a cloud of interstellar gas and dust that reflects the light of neighboring stars. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. reflection reflection plane Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language