Meaning

• Emotionally hardened; unfeeling and indifferent to the suffering/feelings of others.

  "She was so callous that she could criticise a cancer patient for wearing a wig."

• Having calluses.

Meaning

• 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.

• The new formation over the end of a cutting, before it puts out rootlets.

• A shining area on the frons of many species of Tabanomorpha (horse flies and relatives).