The Collaborative International Dictionary
Gneissoid \Gneis"soid\ (-soid), a. [Gneiss + -oid.] Resembling gneiss; having some of the characteristics of gneiss; -- applied to rocks of an intermediate character between granite and gneiss, or mica slate and gneiss.
Wiktionary
a. (context geology English) Having a structure similar to that of gneiss, or intermediate between that of gneiss and mica or granite n. (context geology English) A metamorphic rock having the composition of a laminated granite
Usage examples of "gneissoid".
Drifts piled high in bleak ravines, and the grim gneissoid crags were begirt with gigantic icicles.
The mountain chain is built up of granite, gneissoid, and schistose rocks, often in vertical position, and capped with trachyte and porphyry.
Drifts piled high in bleak ravines, and the grim gneissoid crags were begirt with gigantic icicles.