(1):
(n.) A dark, crystalline, igneous rock, chiefly pyroxene with labradorite.
(2):
(n.) A dark-colored, basic, igneous rock, composed essentially of pyroxene and a triclinic feldspar with magnetic iron. By many authors it is considered equivalent to a coarse-grained basalt.
(3):
(n.) Any dark, igneous rock composed chiefly of silicates of iron and magnesium with some feldspar.
(4):
(n.) Diabase.
(5):
(n.) Coarse-grained basalt.