Prevent means to stop something from happening or to hinder its progress. Antonyms for prevent could be words like allow, permit, aid, assist, encourage, promote, or enable. If you allow or permit something to happen, then you choose not to prevent it. Instead of preventing an event, you may aid or assist it by providing whatever support is necessary for the occurrence. Similarly, if you encourage or promote something, you are pushing for its occurrence. Enabling something could mean providing the necessary tools or resources for its success. Essentially, antonyms for prevent all relate to actions that allow something to occur or progress without interference.