|a fool or simpleton; ninny.|
|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|
|a. the emission of light or other radiation from atoms or molecules that are bombarded by particles, such as electrons, or by radiation from a separate source. The bombarding radiation produces excited atoms, molecules, or ions and these emit photons as they fall back to the ground state|
|b. such an emission of photons that ceases as soon as the bombarding radiation is discontinued|
|c. such an emission of photons for which the average lifetime of the excited atoms and molecules is less than about 10--8 seconds|
|2.||Compare phosphorescence the radiation emitted as a result of fluorescence|
fluorescence fluo·res·cence (fl&oobreve;-rěs'əns, flô-)
The emission of electromagnetic radiation, especially of visible light, stimulated in a substance by the absorption of incident radiation and persisting only as long as the stimulating radiation is continued.
The property of emitting such radiation.
|fluorescence (fl-rěs'əns) Pronunciation Key
The emission of light from an object as a result of bombardment by other kinds of electromagnetic radiation, such as x-rays or ultraviolet rays. Fluorescent materials may appear one color when bathed in visible light and another color when exposed to other kinds of electromagnetic radiation.
Note: “Black light” depends on fluorescence for its effects.