̷ ̷ˌ ̷ ̷ ̷ ̷ˈlāshən noun
( -s )
Etymology: Late Latin annihilation-, annihilatio, from annihilatus + Latin -ion, -io -ion
1. : the act of annihilating or state of being annihilated
the annihilation of the individual is the worst perversity of man — W.L.Sullivan
2. : cessation of being : nothingness
sentient beings are doomed to complete annihilation — C.R.Darwin
3. : the process whereby an electron and a positron unite and consequently lose their identity as particles transforming themselves into short gamma rays — see annihilation radiation