Definition of precipitation in US English:



  • 1Chemistry
    The action or process of precipitating a substance from a solution.

    • ‘Cell debris was removed by centrifugation, and the supernatant was fractionated by ammonium sulfate precipitation.’
    • ‘Acidic proteins are known to trigger carbonate precipitation via matrix mediated processes in microbialites.’
    • ‘Making ripened cheese is a three-step process: coagulation and precipitation of the curd, concentration of the curd, and ripening.’
    • ‘The most common type of substitution reactions of compounds of metals is ion exchange accompanied by precipitation.’
    • ‘The answer is probably related to the size of melt reservoirs and the kinetics of zircon solution and precipitation.’
  • 2Rain, snow, sleet, or hail that falls to the ground.

    • ‘Weather forecast: precipitation in the morning, rain in the afternoon.’
    • ‘If the rising air is humid enough, water vapor in it will condense into clouds and maybe precipitation.’
    • ‘The cold, but dry weekend I expected would now feature some precipitation, possibly snow or freezing rain, on Sunday.’
    • ‘From one third to two-thirds of the precipitation falls as snow.’
    • ‘As air rises, it cools, and its humidity begins condensing into clouds and precipitation.’
    • ‘The past few weeks have been stormy ones, but at resort level, precipitation is still falling as rain.’
    • ‘Eventually saturation occurs and precipitation falls and downdrafts occur.’
    • ‘If you have ever driven through dense precipitation such as rain, snow, sleet, or through fog, then you know the potential danger, especially when your vehicle is not equipped to face such conditions.’
    • ‘Rising motion and the associated low pressure favor precipitation and storm formation.’
    • ‘In places where the warmer air extends to the ground, the precipitation will fall as rain.’
    • ‘The end of August could lead to earlier nights and the odd spell of seasonal weather mixed in with unusual conditions, with precipitation likely where rain falls.’
    • ‘Rain is the precipitation of condensed water vapor caused when a warm front meets a cold front in the upper atmosphere.’
    • ‘This means that as the annual number of days with precipitation will tend to fall, the possibility of convective rainfall leading to copious rainfall in torrential rains will increase.’
    • ‘This forecast was based on the assumption that normal precipitation would fall through May 1.’
    • ‘The region has cool temperatures and frequent precipitation, fog, heavy cloud cover, and strong winds.’
    • ‘A potent threat to the environment of industrialized countries and their neighbors, acid rain occurs when precipitation picks up industrial chemicals as it falls to earth.’
    • ‘Acid rain refers to any precipitation, rain or snow, that's more acid than ordinary rain or snow.’
    • ‘So much rain has fallen that precipitation deficits from last year's drought have been eliminated.’
    • ‘These clouds can also produce Virga, which is when precipitation falls but evaporates before it reaches the ground.’
    • ‘And then it struck me that English does in fact distinguish precipitation from the stuff after it hits the ground.’
    frozen rain, hailstones, sleet
    View synonyms
  • 3archaic The fact or quality of acting suddenly and rashly.

    ‘Cora was already regretting her precipitation’


Late Middle English (denoting the action of falling or throwing down): from Latin praecipitatio(n-), from praecipitare ‘throw down or headlong’ (see precipitate).