competition vs semifinal

competition

noun
  • The competitors in such a contest. 

  • A contest for a prize or award. 

  • The action of competing. 

semifinal

noun
  • A competition that narrows a field of contestants (semifinalists) to a set of finalists, for a subsequent final. 

  • A playoff in the round with only four players or teams left, the stage before the final. 

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