n. pl. mag·ma·ta (-mätə) or mag·mas
1. Geology The molten rock material under the earth's crust, from which igneous rock is formed by cooling.
2. Pharmacology A suspension of particles in a liquid, such as milk of magnesia.
3. A mixture of finely divided solids with enough liquid to produce a pasty mass.
4. Archaic The residue of fruits after the juice has been expressed; pomace.
[Middle English, sediment, dregs, from Latin, from Greek, unguent, from massein, mag-, to knead; see mag- in the Appendix of Indo-European roots.]
mag·matic (-mătĭk) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 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.