the world > the earth > structure of the earth > constituent materials > rock > [noun] > a rock (28)
A rock, cliff, crag; a mass of rock; rocky ground. Obsolete.
A rock; (also) a rocky bank or hillside. Now rare (in later use only in French contexts).
(a) Chiefly U.S. Any of various kinds of (frequently hard or black) rock, stone, etc. (see quots.); (also) gen. a hard stone. Also niggerhead stone…