ˈdaʊnfɔːl heɪst ˈhʌɹ.i pɹɪˌsɪpɪˈteɪʃən overly eager speed (and possible carelessness) he soon regretted his haste an unexpected acceleration or hastening he is responsible for the precipitation of his own demise the act of casting down or falling headlong from a height the falling to earth of any form of water (rain or snow or hail or sleet or mist) the process of forming a chemical precipitate the quantity of water falling to earth at a specific place within a specified period of time the storm brought several inches of precipitation