callus

an area of skin that is thick or hard from continual pressure or friction (as the sole of the foot)

bony tissue formed during the healing of a fractured bone

(botany) an isolated thickening of tissue, especially a stiff protuberance on the lip of an orchid

cause a callus to form on; "The long march had callused his feet"

form a callus or calluses; "His foot callused"