Lava

 noun

1. Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from 800 to 1,200 °C (1,470 to 2,190 °F).
2. 
   
3. hot molten or semifluid rock erupted from a volcano or fissure, or solid rock resulting from cooling of this.
4. "tablelands of lava."

Synm: basalt, magma, obsidian, scoria, coulee