n.1 the act of making extinct; the state of being or process of becoming extinct.
2 the act of extinguishing; the state of being extinguished.
3 total destruction or annihilation.
4 the wiping out of a debt.
5 Physics a reduction in the intensity of radiation by absorption, scattering, etc.
Derivatives:
extinctive adj.
Etymology: L extinctio (as EXTINCT)