[ fel-sik ]
/ ˈfɛl sɪk /

adjective Geology.

(of rocks) consisting chiefly of feldspars, feldspathoids, quartz, and other light-colored minerals.
Compare mafic.

Origin of felsic

First recorded in 1910–15; fel(dspar) + s(ilica) + -ic
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Science definitions for felsic

[ fĕlsĭk ]

Relating to an igneous rock that contains a group of light-colored silicate minerals, including feldspar, feldspathoid, quartz, and muscovite. Compare mafic.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.