(of rocks )岩石 formed when magma (= melted or liquid material lying below the earth’s surface) becomes solid, especially after it has poured out of a volcano 火成的(尤指火山喷出的) Oxford Collocations DictionaryIgneous is used with these nouns:- rock
Word Originmid 17th cent.: from Latin igneus (from ignis ‘fire’) + -ous.