lava








noun

  1. the molten, fluid rock that issues from a volcano or volcanic vent.
  2. the rock formed when this solidifies, occurring in many varieties differing greatly in structure and constitution.

noun

  1. magma emanating from volcanoes and other vents
  2. any extrusive igneous rock formed by the cooling and solidification of molten lava

n.1750, from Italian (Neapolitan or Calabrian dialect) lava “torrent, stream,” traditionally from Latin lavare “to wash” (see lave). Originally applied in Italian to flash flood rivulets after downpours, then to streams of molten rock from Vesuvius. Alternative etymology is from Latin labes “a fall,” from labi “to fall.” Lava lamp is attested from 1965, also lava light (reg. U.S., 1968, as Lava Lite).

  1. Molten rock that flows from a volcano or from a crack in the Earth. Most lava flows at a rate of a few kilometers per hour, but rates as high as 60 km (37 mi) per hour have been observed. Lava that contains abundant iron- and magnesium-rich components usually erupts with temperatures between 1,000°C and 1,200°C (1,832deg;F and 2,192°F). Lava that contains abundant silica- and feldspar-rich components usually erupts with temperatures between 800°C and 1,000°C (1,472deg;F and 1,832°F). Compare magma.
  2. The igneous rock formed when this substance cools and hardens. Depending on its composition and the rate at which it cools, lava can be glassy, very finely grained, ropelike, or coarsely grained. When it cools underwater, it cools in pillow-shaped masses. See also aa pahoehoe pillow lava.

A type of igneous rock that is formed when molten magma from a volcano hardens.

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