A banded or foliated metamorphic rock, usually of the same composition as granite.
[German Gneis, probably alteration of Middle High German ganeist, spark (from its appearance), from Old High German gneista.]
gneissic (nīsĭk), gneissoid′ (nīsoid′), gneissose′ (nīsōs′) adj.
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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.