n.

1. 猛然落下（或摔下）；猛冲[U]
2. 急躁；鲁莽；仓促[U]
3. 促成；加速[U]
4. 【化】沉淀[U]
5. 沉淀物[C][U]
6. （雨、雪等的）降下[U][C]
   There will be precipitation on northern hills tonight.

   今夜北面山上有降雨。

7. 雨；雪[U]
8. 降雨（雪）量[U]

n.

1. Chemistry  the action or process of precipitating a substance from a solution.
2. rain, snow, sleet, or hail that falls to or condenses on the ground.
3. archaic the fact or quality of acting precipitately.