obviate vs prevent

obviate

verb
  • To avoid (a future problem or difficult situation). 

  • To anticipate and prevent or bypass (something which would otherwise have been necessary or required). 

adj
  • Synonym of obviative 

noun
  • Synonym of obviative 

prevent

verb
  • To stop (an outcome); to keep from (doing something). 

How often have the words obviate and prevent occurred in a corpus of books? (source: Google Ngram Viewer )