verb · to not be afraid of hurting someone's feelings or being stern regardless of social ties

为了公司的利益，他不得不拉下脸来批评下属。

to look displeased or put on a stern facial expression

他一听到这个消息，立刻拉下脸来。

to put aside one's ego or dignity to perform a task

他拉下脸来向朋友借钱。