to clam up
[phrase form: clam]
01
突然沉默, 拒绝说话
to suddenly become silent or refuse to talk, often because of nervousness, fear, or a desire to keep information secret
例子
Every time the teacher asked him about his weekend, he would clam up and avoid eye contact.
每次老师问他周末过得怎么样时，他都会突然沉默并避免眼神接触。
During the interrogation, the suspect suddenly clam up and refused to answer any more questions.
在审讯过程中，嫌疑人突然闭口不言，拒绝回答任何更多的问题。
