Definition of: basalt

(bə·sôlt′, bas′ôlt) noun
1. A fine-grained, igneous, volcanic rock of high density and dark color, composed chiefly of plagioclase and pyroxene, usually exhibiting a columnar structure.
2. A black, unglazed pottery resembling basalt, developed by Josiah Wedgwood: also ba·salt′ware′. [<L basaltes dark marble]
—ba·sal′tic adjective