Definition from Wiktionary, the free dictionary
From Latin callum.
- A hardened area of the skin (especially on the foot or hand) caused by repeated friction, wear or use.
- The material of repair in fractures of bone; a substance exuded at the site of fracture, which is at first soft or cartilaginous in consistency, but is ultimately converted into true bone and unites the fragments into a single piece.
- (botany) The new formation over the end of a cutting, before it puts out rootlets.
hardened part of the skin
- (intransitive) To form such hardened tissue