An Annihilation

1. The act of destroying or otherwise turning into nothing, or nonexistence
2. The act of destroying the form or combination of parts under which a thing exists, so that the name can no longer be applied to it
3. The state of being annihilated.
4. (physics) The process of a particle and its corresponding antiparticle combining to produce energy.

(act of reducing to nothing): extinction, eradication

(state of being annihilated): extinction

(act of reducing to nothing): creation, generation

(state of being annihilated): generation