A<unk> or clavus (plural clavi or clavuses) is a cone-shaped and often painful inwardly directed callus of dead skin that forms at a pressure point near a bone, or on a weight-bearing part of the body. When on the feet,<unk>  can be so painful as to interfere with walking. The visible portion of the<unk> tends to be more-or-less round, but<unk>  are defined by having a hard tapering root that is directed inward, and pressure on the<unk> pushes this root deeper into the flesh. (Thus the Latin term clavus 'nail'.) Pressure<unk>  usually occur on thin or glabrous (hairless and smooth) skin surfaces, especially on the dorsal surface of toes or fingers, but<unk>  triggered by an acute injury (such as a thorn) may occur on the thicker skin of the palms or bottom of the feet (palmar<unk>  and plantar<unk> . Pressure<unk>  form when chronic pressure on the skin against an underlying bone traces a usually elliptical path during the rubbing motion. The<unk> forms at the center of the pressure point and gradually widens and deepens.<unk>  from an acute injury, such as a from a thorn in the sole of the foot, may form due to the weight of the body, when the process that creates the usually evenly developing plantar callus is concentrated at the point of the healing injury, as an internal callus may be triggered by pressure on the transitional scar tissue. Once formed, the<unk> itself becomes the pressure point that generates the callus. Plantar<unk>  are superficially similar to plantar warts, but the cause and treatment are very different.
Corn 
Whitlow
Wellbee
Squawk 
Wart
Drustbed
Cowlick
Sniffle