SG Heritage Dictionary

Callus [Noun] Webster's Dictionary 1828

Any cutaneous, corneous, or bony hardness, but generally the new growth of osseous matter between the extremities of fractured bones, serving to unite them; also a hardness in the skin; a hard, dense, insensible knob on the hands, feet, etc.

Callus [Noun] Webster's Dictionary 1913

1. Same as Callosity

2. The material of repair in fractures of bone; a substance exuded at the site of fracture, which is at first soft or cartilaginous in consistence, but is ultimately converted into true bone and unites the fragments into a single piece.

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