Annihilation's defined as "total destruction" or "complete obliteration" of an object; having its root in the Latin nihil (nothing). A literal translation's "to make into nothing". Annihilation's the opposite of exnihilation, which means "to create something out of nothing". In physics, the word's used to denote the process that occurs when a subatomic particle collides with its respective antiparticle. Since energy and momentum must be conserved, the particles aren't actually made into nothing… (More on Annihilation)