from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Containing a group of light-colored silicate minerals that occur in igneous rocks.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium.
- n. A rock with such properties.
fel(dspar) + s(ilica) + -ic.(American Heritage® Dictionary of the English Language, Fourth Edition)
Blend of feldspar and silica, with the suffix -ic. (Wiktionary)