1. destroy utterly; obliterate: "a simple bomb of this type could annihilate them all"
▪ defeat utterly: "the stronger force annihilated its opponent virtually without loss"
▪ convert (a subatomic particle) into radiant energy.
Word Originlate Middle English (originally as an adjective meaning ‘destroyed, annulled’): from late Latin annihilatus ‘reduced to nothing’, from the verb annihilare, from ad- ‘to’ + nihil ‘nothing’. The sense ‘destroy utterly’ dates from the mid 16th century.