ˈmeləˌfī(ə)r noun
( -s )
Etymology: French mélaphyre, from méla- mela- + -phyre
1. : a porphyritic rock consisting of phenocrysts of feldspar in a dark groundmass ; broadly : a porphyritic igneous rock with dark-colored aphanitic groundmass and phenocrysts of various kinds
2. : a Mesozoic basalt