n.
Pronunciation: ' r ī - ə - ˌ l ī t
Function: noun
Etymology: German Rhyolith, from Greek rhyax stream, stream of lava (fr. rhein ) + German -lith -lite
Date: 1868
: a very acid volcanic rock that is the lava form of granite
– rhy · o · lit · ic \ ˌ r ī - ə - ' li-tik \ adjective