/ Dictionary / Index M magnesium light: Meaning and Definition of Find definitions for: magne'sium light" Pronunciation: [key] the strongly actinic white light produced when magnesium is burned: used in photography, signaling, pyrotechnics, etc. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. magnesium hydroxide magnesium oxide Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language