Crossword Dictionary

What's The Definition Of Volcanic?

\Vol*can"ic\, a. [Cf. F. volcanique, It. vulcanico.] 1. Of or pertaining to a volcano or volcanoes; as, volcanic heat. 2. Produced by a volcano, or, more generally, by igneous agencies; as, volcanic tufa. 3. Changed or affected by the heat of a volcano. {Volcanic bomb}, a mass ejected from a volcano, often of molten lava having a rounded form. {Volcanic cone}, a hill, conical in form, built up of cinders, tufa, or lava, during volcanic eruptions. {Volcanic foci}, the subterranean centers of volcanic action; the points beneath volcanoes where the causes producing volcanic phenomena are most active. {Volcanic glass}, the vitreous form of lava, produced by sudden cooling; obsidian. See {Obsidian}. {Volcanic mud}, fetid, sulphurous mud discharged by a volcano. {Volcanic rocks}, rocks which have been produced from the discharges of volcanic matter, as the various kinds of basalt, trachyte, scoria, obsidian, etc., whether compact, scoriaceous, or vitreous.