preÂ·cipÂ·iÂ·taÂ·tion (prÄ­-sÄ­pâ²Ä­-tÄâ²shÉn) A form of water, such as rain, snow, or sleet, that condenses from the atmosphere and falls to the Earth's surface. precipitate, precipitation - Precipitate is from Latin praecipitare, to throw or drive headlong; precipitation first meant the action of falling or throwing down.