From Longman Dictionary of Contemporary Englishigneousig‧ne‧ous /ˈɪɡniəs/ adjective technical HEGigneous rocks are formed from lava (=hot liquid rock)
Examples from the Corpus
igneous• Auger spectroscopy of igneous and metamorphic rocks has shown fine films of carbon covering grain boundaries.• The same structural features, sometimes less easily recognized, are found in igneous and metamorphic rocks.• Thus it is very well developed on fine-grained basic igneous and metamorphic rocks.• At a later time, according to Hutton, subterranean heat may produce an intrusion of igneous rock.• Though igneous rocks are not layered, as sediments are, they too have characteristics that place them in time.• Granulites are like their textural equivalents, granular igneous rocks, in being mosaics of interlocking crystals of roughly equal size.• Extensive areas within continental platforms are formed of basement, a complex of metamorphic and igneous rocks of Palaeozic or Precambrian age.• Which are these hills of igneous rocks?Origin igneous (1600-1700) Latin igneus, from ignis; → IGNITE 