tight-lipped

Từ điển Oxford Advanced Learner 8th

ˌtight-ˈlipped [tight-lipped] BrE NAmE adjective
1. not willing to talk about sth
•Despite the rumours, government officials remained tight-lipped today.
2. keeping your lips pressed firmly together, especially because you are angry about sth
•He marched out of the room tight-lipped and white-faced.
•a tight-lipped reply