precipitation

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A headlong fall or rush.
2. n. Abrupt or impulsive haste.
3. n. A hastening or acceleration, especially one that is sudden or unexpected: He is responsible for the precipitation of his own demise.
4. n. Meteorology Any form of water, such as rain, snow, sleet, or hail, that falls to the earth's surface.
5. n. Meteorology The quantity of such water falling in a specific area within a specific period.
6. n. Chemistry The process of separating a substance from a solution as a solid.

Century Dictionary and Cyclopedia

1. n. The act of casting down from a height, or the state of being flung or hurled downward.
2. n. Rapid motion; a hurrying or rushing onward.
3. n. Haste; hurry; unwise or rash rapidity.
4. n. In chem., the process by which any substance is made to separate from another or others in solution, and fall to the bottom.
5. n. Moisture from the atmosphere deposited on the earth's surface, including dew, mist, rain, frost, snow, sleet, hail, etc.

Wiktionary

1. n. meteorology Any or all of the forms of water particles, whether liquid or solid, that fall from the 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.
2. n. A hurried headlong fall.
3. n. countable, 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.
4. n. figuratively Unwise or rash rapidity; sudden haste.

GNU Webster's 1913

1. n. The act of precipitating, or the state of being precipitated, or thrown headlong.
2. n. A falling, flowing, or rushing downward with violence and rapidity.
3. n. Great hurry; rash, tumultuous haste; impetuosity.
4. n. (Chem.) The act or process of precipitating from a solution.
5. n. (Meteorology) A deposit on the earth of hail, mist, rain, sleet, or snow; also, the quantity of water deposited.

WordNet 3.0

1. n. the quantity of water falling to earth at a specific place within a specified period of time
2. n. the falling to earth of any form of water (rain or snow or hail or sleet or mist)
3. n. the process of forming a chemical precipitate
4. n. the act of casting down or falling headlong from a height
5. n. an unexpected acceleration or hastening
6. n. overly eager speed (and possible carelessness)