Callus
<B>1.</B> A localized firm thickening of the upper layer of skin as a result of repetitive friction.
A callus on the skin of the foot has become thick and hard from rubbing (as a result of repetitive friction).
Calluses of the feet may lead to other problems such as serious infections.
Shoes that fit well can keep calluses from forming on the feet.<BR><B>2.</B> The hard new bone substance that forms in an area of bone fracture.
Bony callus is part of the bone repair process.<BR> Also called, less often, a callosity.
Both callus and callosity are derived from the Latin callum meaning thick skin.