fluorescence

noun

fluo·​res·​cence flu̇-ˈre-sᵊn(t)s 

flȯ-

: luminescence that is caused by the absorption of radiation at one wavelength followed by nearly immediate reradiation usually at a different wavelength and that ceases almost at once when the incident radiation stops

also : the radiation emitted compare phosphorescence

Synonyms of fluorescence

• glow
• glare
• light
• gleam
• luminescence
• illumination

Examples of fluorescence in a Sentence

studied the fluorescence of certain elements

Recent Examples on the Web

After all, microscopic analysis and portable X-ray fluorescence simply weren’t options in the 1920s. —Ryan Brennan, Kansas City Star, 13 Feb. 2026

To delineate the murine C3aR coding sequence, gene structure, 5′-flanking region, and chromosome location, cDNA and genomic clones encoding the mouse C3a receptor were isolated, characterized, and used in fluorescence in situ hybridization experiments. —Kirstin R.w. Matthews, STAT, 3 Feb. 2026

Smith’s novel digital video fluorescence microscope was designed to take movies of neuronal activity using fluorescent light. —Ingrid Wickelgren, Quanta Magazine, 30 Jan. 2026

No intrusive blood samples will need to be taken, and the fluorescence signal will continue for as long as the inflammation lasts. —New Atlas, 14 Jan. 2026

Word History

Etymology

fluorspar + opalescence

First Known Use

1852, in the meaning defined above

Rhymes for fluorescence

• excrescence
• quiescence
• quintessence
• senescence
• acquiescence
• adolescence
• coalescence
• convalescence
• effervescence
• efflorescence
• evanescence
• incandescence

Kids Definition

fluorescence

noun

flu·​o·​res·​cence

ˌflu̇(-ə)r-ˈes-ᵊn(t)s

: the giving off of radiation usually as visible light when exposed to radiation from another source (as ultraviolet light)

also : the radiation given off

Medical Definition

fluorescence

noun

flu·​o·​res·​cence -ˈes-ᵊn(t)s 

: luminescence that is caused by the absorption of radiation at one wavelength followed by nearly immediate reradiation usually at a different wavelength and that ceases almost immediately when the incident radiation stops

also : the radiation emitted

fluorescent

-ˈes-ᵊnt 

adjective

fluorescently adverb