/ Dictionary / Index O Orion Nebula: Meaning and Definition of Find definitions for: Ori'on Neb"ula Pronunciation: [key] — Astron. Astron. a luminous nebula in the constellation Orion, in the center of Orion's sword. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Orionids Oriskany Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language