B2 (使)平静;(使)冷静;(使)镇静to stop feeling upset, angry, or excited, or to stop someone feeling this way
She sat down and took a few deep breaths to calm herself down. 她坐下做了几个深呼吸让自己平静下来。
She was angry at first but we managed to calm her down. 一开始她很生气,但我们设法让她平静了下来。
Calm down, for goodness sake. It's nothing to get excited about! 看在上帝的份上,安静下来吧。没什么可激动的!