Definition of poikiloblast in English:
poikiloblast
(also poeciloblast)
noun ˈpɔɪkɪlə(ʊ)blɑːstˈpɔɪkɪlə(ʊ)blast
Geology. A large crystal in a metamorphic rock containing inclusions or small grains of other minerals.
Origin
Late 19th century (in an earlier sense). From poikilo- + -blast.