This is the 4080th most frequent Chinese word.
匆匆
Hastily; hurriedly.
In this sentence, '匆匆' is used to describe someone's hurried manner of action.
他匆匆忙忙地离开了家。
He left home in a hurry.
Here, '匆匆' indicates the rapidity and urgency of the writing process.
会议开始后,他匆匆写下几条重要的笔记。
After the meeting started, he quickly wrote down a few important notes.
In this instance, '匆匆' is metaphorically applied to describe the swift passage of time.