Definition
to reduce one's anger or excitement about a situation
平静下来
After the argument, he needed some time to simmer down.
争吵过后，他需要一些时间冷静下来。
Her emotions were running high, and her friend suggested she take deep breaths to simmer down.
她的情绪很激动，朋友建议她深呼吸来平静下来。
When you feel angry, it's best to step away for a bit until you can simmer down before returning.
当你感到生气时，最好先离开一下，直到你能冷静下来再回来。