unchallenged /ʌnˈtʃælɪndʒd/ star1

• 1.  

  ADJ（形容词） When something goes unchallenged or is unchallenged, people accept it without asking questions about whether it is right or wrong. 未受到过质疑的

  例：

  These views have not gone unchallenged.

  这些观点并非没有受到过质疑。

• 2.  

  ADJ（形容词） If you say that someone's position of authority is unchallenged, you mean that it is strong and no one tries to replace them. (地位、权威等) 未受到过挑战的

  例：

  He is the unchallenged leader of the chess club.

  他是该国际象棋俱乐部未受到过挑战的领导人。