callus

Noun

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

• bony tissue formed during the healing of a fractured bone

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

Verb

• form a callus or calluses
  • His foot callused
    

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