The light emitted by an incandescent object while cooling.
1984, Paul Auster (as Paul Benjamin), Squeeze Play, London: Faber & Faber, 1991, Chapter 19, p. 176,
Nothing will matter to you more than that [base]ball. It will hold you so completely that when you at last file out and return to the normal world, it will stay with you like the afterglow of a flashbulb that’s gone off in your eyes.
The light emitted by a phosphor after excitation.
The mildly euphoric feeling experienced after a pleasurable experience, especially after an orgasm or drug-induced high.
An afterparty.
There's an afterglow with singing after the evening worship.