action intended to nullify the effects of some previous action

(euphemism) the removal of a threat by killing or destroying it (especially in a covert operation or military operation)

a chemical reaction in which an acid and a base interact with the formation of a salt; with strong acids and bases the essential reaction is the combination of hydrogen ions with hydroxyl ions to form water

the phonological process in which phonemic distinctions between sounds are lost or neutralized in specific phonetic contexts, resulting in a single phonetic realization