igneousPronunciation: /ˈɪgnɪəs/Definition of igneous adjective Geology (of rock) having solidified from lava or magma. relating to or involving volcanic or plutonic processes:igneous activity rare of fire; fiery. Origin: mid 17th century: from Latin igneus (from ignis 'fire') + -ousigneous in other Oxford dictionaries Definition of igneous in the US English dictionary
