| noun | an area of skin that is thick or hard from continual pressure or friction (as the sole of the foot) |
| noun | bony tissue formed during the healing of a fractured bone |
| noun | (botany) an isolated thickening of tissue, especially a stiff protuberance on the lip of an orchid |
| verb | cause a callus to form on “The long march had callused his feet” |
| verb | form a callus or calluses “His foot callused” |
| callous | adjective | having calluses; having skin made tough and thick through wear |
| callus | verb | cause a callus to form on |
| callus | noun | an area of skin that is thick or hard from continual pressure or friction (as the sole of the foot) |