a. Any form of water, such as rain, snow, sleet, or hail, that falls to the earth's surface.
b. The quantity of such water falling in a specific area within a specific period.
2. A hastening or acceleration, especially one that is sudden or unexpected: He is responsible for the precipitation of his own demise.
3. Abrupt or impulsive haste.
4. A headlong fall or rush.
5. Chemistry The process of separating a substance from a solution as a solid.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.