gnash one's teeth 咬牙切齿
gnash teeth 磨牙
A: Why is he gnashing his teeth like that?
A：他为什么那样咬牙切齿的？
B: He is extremely frustrated with the situation.
B：他对现状感到非常沮丧。
1) 咬牙切齿
2) 磨牙
3) 咬紧牙关
1. 咬牙切齿；磨牙
verb
1. to clatter the teeth together, especially when angry or in pain
Synonym: grind