straighten one's face

Verb

To cease laughing or smiling, etc., and compose one's features.

Japanese Meaning

笑顔や笑いをやめ、顔の表情を整え真剣な様子にする / 表情を引き締め、普段の笑みから真面目な顔に戻す

In public, it's important to straighten one's face and appear confident.

人前では、笑顔をやめて表情を引き締め、堂々と見えることが大切だ。

Sense（1）

To cease laughing or smiling, etc., and compose one's features.

straightens one's face

（ present singular third-person ）

straightening one's face

（ participle present ）

straightened one's face

（ participle past ）

straightened one's face

（ past ）