flu·o·resce \(ˈ)flu̇(ə)|res, (ˈ)flōrˌes, (ˈ)flȯ|res\verb (-ed/-ing/-s) Etymology: back-formation from fluorescence & fluorescent intransitive verb : to produce, undergo, or exhibit fluorescence transitive verb : to produce (color) in fluorescing < fluoresces a dark red color under ultraviolet irradiation >