Synonyms: volcanic
Definition: igneous rock produced by eruption and solidified on or near the earth's surface; rhyolite or andesite or basalt
Usage: volcanic rock includes the volcanic glass obsidian
Similar words: extrusive
Definition: of rock material; forced out while molten through cracks in the earth's surface
Synonyms: volcanic
Definition: explosively unstable
Usage: a volcanic temper
Similar words: unstable
Definition: lacking stability or fixity or firmness
Usage: unstable political conditions; the tower proved to be unstable in the high wind; an unstable world economy