/ Dictionary / Index L luciferin: Meaning and Definition of Find definitions for: lu•cif•er•in Pronunciation: (l-sif'ur-in), [key] — n. Biochem. a pigment occurring in luminescent organisms, as fireflies, that emits light when undergoing oxidation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: luciferin (Thesaurus) Lucifer lucifer match Related Content Daily Word Quiz: cetacean Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language