The word "obviate" means to prevent or avoid the occurrence of something. There are several synonyms for this word that can be used in different situations. One such synonym is "preclude", which means to make something impossible or prevent it from happening. Another one is "avert", which means to divert or turn away something. "Forestall" is another synonym, which means to prevent something from happening by taking an early action. "Thwart" is another synonym which means to stop or prevent something from happening. All of these synonyms can be used to express the idea of preventing or avoiding something.