1. A white amorphous powder, Ca3(PO4)2, used in ceramics, rubber, fertilizers, and plastic stabilizers and as a food supplement.
2. A dibasic white crystalline powder, CaHPO4, used as an animal food, as a plastic stabilizer, and in glass and toothpaste.
3. A monobasic colorless deliquescent powder, Ca(H2PO4)2, used in baking powders, as a plant food, as a plastic stabilizer, and in glass.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.