|1.||See also peptic ulcer a disintegration of the surface of the skin or a mucous membrane resulting in an open sore that heals very slowly|
|2.||a source or element of corruption or evil|
|[C14: from Latin ulcus; related to Greek helkos a sore]|
|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
ulcer ul·cer (ŭl'sər)
A lesion of the skin or of a mucous membrane, such as the one lining the stomach or duodenum, that is accompanied by formation of pus and necrosis of surrounding tissue, usually resulting from inflammation or ischemia.
Note: It used to be thought that stress was the cause of stomach and duodenal ulcers, but we now know that they are caused by bacteria and can be cured by antibiotics.