fluo·res·cent (fl-rĕsənt, flô-, flō-)
a. Of or relating to fluorescence.
b. Exhibiting or produced by fluorescence: fluorescent corals; fluorescent light.
2. Glowing as if with fluorescence; vivid: bright fluorescent colors.
3. Of or relating to a light bulb that produces visible light by fluorescence, especially a glass tube whose inner wall is coated with a material that fluoresces when an electrical current causes a vapor within the tube to discharge photons.
1. A fluorescent light bulb.
2. A lamp that is fitted with a fluorescent light bulb.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.