A hardened area of the skin (especially on the foot or hand) caused by repeated friction, wear or use.
A shining area on the frons of many species of Tabanomorpha (horse flies and relatives).
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.
To form such hardened tissue.
Any other mark or stain left on a surface from a sliding or rubbing object.
Any burn on the skin caused by scraping the skin against a surface.
A black mark left on a road surface from the sliding or skidding tires of a motor vehicle that has lost traction.
A visible feces stain left on underpants, trousers, or sometimes the toilet bowl.
A mark of a soiled finger wiped on a surface.