callus
noun
1. an area of skin that is thick or hard from continual pressure or friction (as the sole of the foot)
Similar word(s): callosity
Definition categories: state, hardening
2. bony tissue formed during the healing of a fractured bone
Definition categories: state, cicatrice, cicatrix, scar
3. (botany) an isolated thickening of tissue, especially a stiff protuberance on the lip of an orchid