- [uncountable] (specialist)
rain, snow, etc. that falls; the amount of this that falls 降水，降水量（包括雨、雪、冰等） There is heavy precipitation in some parts of the country. 该国一些地区降雨量很大。 Acid precipitation may cause a reduction in forest productivity. 酸性降水可能导致森林生产力下降。 an increase in annual precipitation 年降水量的增加 Annual precipitation ranges from 500 to 2 200 mm. 年降水量从500毫米到2 200毫米不等。 In these areas precipitation was formerly too low to support growth. 在这些地区，以前的降雨量太低，不足以支撑增长。
- [uncountable, countable] (
chemistry 化学 a chemical process in which solid material is separated from a liquid 沉淀；淀析 calcium phosphate precipitation 磷酸钙沉淀
Word Originlate Middle English (denoting the action of falling or throwing down): from Latin praecipitatio(n-), from praecipitare ‘throw down or headlong’, from praeceps, praecip(it)- ‘headlong’, from prae ‘before’ + caput ‘head’.