Synonyms for prevent

verb

to prevent is to stop or keep from happening or doing, as by some prior action or by interposing an obstacle or impediment to prevent disease, to prevent them from leaving; forestall suggests advance action to stop something in its course or make it ineffective try to forestall their questions; preclude implies making impossible by shutting off every possibility of occurrence locked doors precluded my escape ; obviate suggests the preventing of some unfavorable outcome by taking necessary anticipatory measures her frankness obviated objections; avert suggests a warding off of imminent danger or misfortune hoping that diplomacy would avert war