From Longman Dictionary of Contemporary Englishthe king of somethingthe king of somethingsomeone or something that people think is the most important or best of a particular type of person or thing the King of Rock ‘n’ Roll the king of Swiss cheeses The lion is the king of the jungle. → king
Examples from the Corpus
the king of the jungle• Have you seen how the king of the jungle behaves when the missus brings back a nice bit of venison? 