coward

你不敢跟她说话？你这个懦夫！

You didn't talk to her? You ___coward!

他因为拒绝参加抗议而被称作懦夫。

He was called a ___coward for refusing to join the protest.

他总是逃避挑战；他是个彻头彻尾的懦夫。

He always runs away from challenges; he's a total ___coward.