luciferin
noun
lu·cif·er·in lü-ˈsi-f(ə-)rən 
: any of various organic substances in luminescent organisms (such as fireflies) that upon oxidation produce a virtually heatless light
Did you know?
Luciferin got its name from the Latin word lucifer (meaning "light-bearing"), which is also a source of the word that is sometimes used as a name of the devil. We won't go into how Lucifer came to be called by that name-suffice it to say he wasn't always associated with darkness-but we will look a bit more closely at the Latin word lucifer. It comes from Latin luc-, meaning "light," plus -fer, meaning "bearing" or "producing." Additional relatives include the nontechnical adjective luciferous, meaning "bringing light or insight," and luciferase, the enzyme that catalyzes the oxidation of luciferin.
Example Sentences
Recent Examples on the Web For example, in order to do their glowing thing, fireflies use firefly luciferin or (4S)-2-(6-hydroxy-1,3-benzothiazol-2-yl)-4,5-dihydrothiazole-4-carboxylic acid, which looks like a ridiculously strong password. 
Bruce Y. Lee, Forbes, 3 Nov. 2021 Dumping firefly luciferin on plants is extremely expensive and can be toxic. John Timmer, Ars Technica, 30 Apr. 2020 The light is produced inside the tiny dinoflagellates body thanks to two chemicals: the enzyme luciferase and the compound luciferin. Stacey Leasca, Travel + Leisure, 27 Apr. 2020 Bioluminescence comes in a range of greens, reds and blues, and it’s caused by a protein called luciferin, often found in marine animals, mushrooms, insects, algae and specific types of bacteria. Jill Langlois, Smithsonian, 5 Dec. 2019 Just four luciferins are responsible for most of the light production in the ocean. Quanta Magazine, 1 Dec. 2016 Some species of dinoflagellates light up using a similar to chemical reaction to that of fireflies; both use a naturally occurring molecule called luciferin, named for Lucifer, the light-bearer. Liz Langley, National Geographic, 2 May 2019 Curiously, there are far fewer luciferins than luciferases. Quanta Magazine, 1 Dec. 2016 While species tend to have unique luciferases, many share the same luciferin. Quanta Magazine, 1 Dec. 2016 See More
Bruce Y. Lee, Forbes, 3 Nov. 2021 Dumping firefly luciferin on plants is extremely expensive and can be toxic. John Timmer, Ars Technica, 30 Apr. 2020 The light is produced inside the tiny dinoflagellates body thanks to two chemicals: the enzyme luciferase and the compound luciferin. Stacey Leasca, Travel + Leisure, 27 Apr. 2020 Bioluminescence comes in a range of greens, reds and blues, and it’s caused by a protein called luciferin, often found in marine animals, mushrooms, insects, algae and specific types of bacteria. Jill Langlois, Smithsonian, 5 Dec. 2019 Just four luciferins are responsible for most of the light production in the ocean. Quanta Magazine, 1 Dec. 2016 Some species of dinoflagellates light up using a similar to chemical reaction to that of fireflies; both use a naturally occurring molecule called luciferin, named for Lucifer, the light-bearer. Liz Langley, National Geographic, 2 May 2019 Curiously, there are far fewer luciferins than luciferases. Quanta Magazine, 1 Dec. 2016 While species tend to have unique luciferases, many share the same luciferin. Quanta Magazine, 1 Dec. 2016 See More Word History
Etymology
International Scientific Vocabulary, from Latin lucifer light-bearing
First Known Use
1888, in the meaning defined above
Medical Definition
luciferin
noun
lu·cif·er·in -(ə-)rən
: any of various organic substances in luminescent organisms that furnish practically heatless light in undergoing oxidation promoted by luciferase