Lava n. : 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.

Example:
my Lava lamp is sitting in a glob, how do i make it work?

Taxonomy
lava, lava flow, eruption, Pāhoehoe, viscosity, lava dome, volcano, Lava tubes, Pillow lava, temperatures, basalt, viscous, fragments, volcanoes, crust, rock, magma, molten rock.

Defination from the web:
lavas tend to produce low-profile shield volcanoes or "flood basalt fields", because the fluidal lava flows for long distances from the vent. ... Lavas with high viscosity are rhyolite, dacite, andesite and trachyte, with cooled basaltic lava also quite viscous; those with low viscosities ...