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.
Dirt, or a stain.
A chirp of radiation power from an astronomical body that has a smeared appearance on its plot in the time-frequency plane (usually associated with massive bodies orbiting supermassive black holes)
A stain on somebody's reputation.
To harm the reputation of; to smear or slander.
To dirty; to make dirty.