quenching

noun4

1. •
   The extinction of any of several physical properties.
2. •
   The rapid cooling of a hot metal object, by placing it in a liquid, in order to harden it.
3. •
   A process in which a galaxy loses cold gas, thus strongly suppressing star formation.
4. •
   The dissipation of energy from light in excess of what can be used for photosynthesis.