noun

• (meteorology) Any or all of the forms of water particles, whether liquid or solid, that fall from the upper atmosphere (e.g., rain, hail, snow or sleet). It is a major class of hydrometeor, but it is distinguished from cloud, fog, dew, rime, frost, etc., in that it must fall. It is distinguished from cloud and virga in that it must reach the ground.
  "South Korea’s Ministry of Environment said in a news release that no major precipitation was observed after the cloud seeding operation."
• (meteorology) The amount of water precipitated in any form.
• (countable, uncountable, chemistry) A reaction that leads to the formation of a heavier solid in a lighter liquid; the precipitate so formed at the bottom of the container.
• (figuratively) Unwise or rash rapidity; sudden haste.
  "Immediately on returning home, highly satisfied with the result of his visit to Mrs. Belmour, Melliphant found on his table a letter from Sir Howard, over which he cast his eyes with precipitation."