La"va (lä"vȧ; 277), n. [It.
lava lava, orig. in Naples, a torrent of rain overflowing the
streets, fr. It. & L. lavare to wash. See Lave.]
The melted rock ejected by a volcano from its top or fissured
sides. It flows out in streams sometimes miles in length. It also
issues from fissures in the earth's surface, and forms beds covering
many square miles, as in the Northwestern United States.
☞ Lavas are classed, according to their structure, as
scoriaceous or cellular, glassy, stony, etc., and according to the
material of which they consist, as doleritic, trachytic, etc.
Lava millstone, a hard and coarse basaltic
millstone from the neighborhood of the Rhine. -- Lava
ware, a kind of cheap pottery made of iron slag cast
into tiles, urns, table tops, etc., resembling lava in
appearance.