Phosphorescent means glowing softly for a while after the light has gone. Phosphorescent paint, a phosphorescent glow, phosphorescent stars.
The delay is what defines it: fluorescence stops the instant the light does, and phosphorescence releases the energy slowly, which is why the stars on a ceiling fade over hours. Note that phosphorus itself is not phosphorescent — it glows by a slow chemical reaction, which is a different thing with a confusingly similar name.
1adjectivephosphorescentGlowing softly for a while after the light has gone.
“The bedroom ceiling was covered with phosphorescent stars that glowed after the lights went out.”
phosphorescent is a quality of glowing.
Phosphorus plus -escent, from Greek phosphoros, light-bearing. Phosphorus was named for the glow, and the two effects were later distinguished.
Latin
phōsphorus
English
phosphorus
English, today
phosphorescent
Built from
From phosphorus + -escent. It's interesting to note that phosphorus is not phosphorescent. Some phosphoric mixtures can be luminescent through chemical reactions, but none exhibit literal phosphorescence. phosphorus Borrowed from Latin phōsphorus. Borrowed from Latin phōsphorus, from Ancient Greek φωσφόρος (“the bearer of light”), from φῶς (“light”) + φέρω (“to bear, carry”).
Etymology from Wiktionary, CC BY-SA