- The definition of lava is hot, molten rock.
Hot molten rock that spews from a volcano is an example of lava.
Lava spewing from a volcano.
lava definition by Webster's New World
- melted rock issuing from a volcano
- such rock when solidified by cooling
Origin: Italian ; from dialect, dialectal (Neapolitan) lave ; from Classical Latin labes, a fall, subsidence ; from labi, to slide ; from Indo-European base an unverified form lāb-, to hang down from source lap, lip
lava definition by American Heritage Dictionary
- Molten rock that reaches the earth's surface through a volcano or fissure.
- The rock formed by the cooling and solidifying of molten rock.
Origin: Italian, perhaps from Latin lābēs, fall, from Latin lābī, to fall.Word History: Lava was appropriately named by people living near Mount Vesuvius. The only active volcano on the European mainland, Vesuvius has erupted frequently since Pompeii and Herculaneum were buried by it in A.D. 79. The Neapolitans who lived in the vicinity took the Italian word lava, meaning “a stream caused suddenly by rain,” and applied it to the streams of molten rock coming down the sides of Vesuvius. The term was then taken into Standard Italian, where it came to mean the rock in both its molten and its solidified states. The Italian word in all its senses was borrowed into English around the middle of the 18th century (1750 being the earliest date of record).
lava - Cultural Definition
lava - Science Definition
- 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.
- 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.