Emily Dickinson Lexicon

LA'VA, n. [probably from flowing, and from the root of L. fluo, or lavo; It. laua, a stream, now lava.]

1. A mass or stream of melted minerals or stony matter which bursts or is thrown from the mouth or sides of a volcano, and is sometimes ejected in such quantities as to overwhelm cities. Catania, at the foot of Etna, has often been destroyed by it, and in 1783, a vast tract of land in Iceland was overspread by an eruption of lava from mount Heela.
2. The same matter when cool and hardened.