Definitions for diabaseˈdaɪ əˌbeɪs
Random House Webster's College Dictionary
a fine-grained gabbro occurring as minor intrusions.
Origin of diabase:
1830–40; < F, =dia- (error for di- two) +basebase1
A fine-grained igneous rock composed mostly of pyroxene and feldspar
a basic, dark-colored, holocrystalline, igneous rock, consisting essentially of a triclinic feldspar and pyroxene with magnetic iron; -- often limited to rocks pretertiary in age. It includes part of what was early called greenstone