/ Dictionary / Index D dark reaction: Meaning and Definition of Find definitions for: dark' reac"tion Pronunciation: [key] the phase of photosynthesis, not requiring light, in which carbohydrates are synthesized from carbon dioxide. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. dark of the moon darkroom Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language