A clod is a lump or mass of earth. The word may describe the crust of sores, soft soil in a valley, or earth covering seed.
Job uses clods for the crust formed over sores and for the clods of the valley. Joel speaks of seed lying beneath clods, while Hosea uses breaking clods figuratively of spiritual discipline.
The underlying words can mean a mass of earth, a soft clod or lump of clay, or something thrown off by a spade.