名詞 precipitation:

1. the quantity of water falling to earth at a specific place within a specified period of time
2. the process of forming a chemical precipitate
3. the falling to earth of any form of water (rain or snow or hail or sleet or mist)
   同義詞：downfall
4. the act of casting down or falling headlong from a height
5. an unexpected acceleration or hastening
6. overly eager speed (and possible carelessness)
   同義詞：haste, hastiness, hurry, hurriedness

1. Precipitation in the form of pellets of ice and hard snow.
   冰雹以冰和硬雪塊顆粒的形式下落
2. The treatment of metal or the separation of metal from ores and ore concentrates by liquid processes, such as leaching, extraction, and precipitation.
   水冶金術(shù)通過(guò)液體過(guò)程，象過(guò)濾，提煉，沉淀等方法處理金屬，從礦石中或礦石濃縮物中分離出金屬
3. There will be precipitation on northern hills tonight.
   今夜北部山區(qū)有降雪。

pre.cip.i.ta.tion

n.（名詞）
A headlong fall or rush.
猛然落下或沖下
Abrupt or impulsive haste.
急躁或沖動(dòng)
A hastening or an acceleration, especially one that is sudden or unexpected:
陡然，促然：尤指突然的或出乎意料的急促或加速：
例句：
He is responsible for the precipitation of his own demise.
他得為自己的卒死負(fù)責(zé)

Abbr. pptn.Meteorology
縮寫(xiě) pptn.【氣象學(xué)】
Any form of water, such as rain, snow, sleet, or hail, that falls to the earth`s surface.
降水：暴雨、雪、凍雪或冰雹降落到地表的任何形式的水
The quantity of such water falling in a specific area within a specific period.
降水量：某一特定時(shí)期內(nèi)特定區(qū)域的降水?dāng)?shù)量
Chemistry The process of separating a substance from a solution as a solid.
【化學(xué)】 沉淀：把物質(zhì)從溶液中分解為固體的過(guò)程