afterglow

Short definition from Wiktionary

Noun

1. 1
   The glow seen in the sky after sunset.
2. 2
   The light emitted by an incandescent object while cooling.
3. 3
   The light emitted by a phosphor after excitation.
4. 4
   The mildly euphoric feeling experienced after a pleasurable experience, especially after an orgasm or drug-induced high.
5. 5
   An afterparty.