NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version. A bezoar is a tightly packed collection of partially digested or undigested material that is unable to exit the stomach. Gastric bezoars are usually rare and can occur in all age groups. They often occur in patients with behavior disorder or abnormal gastric emptying and also after gastric surgery.
verb (used without object), presided, presiding. 1. to occupy the place of authority or control, as in an assembly or meeting; act as president or chairperson. 2. to exercise management or control (usually followed by over): The lawyer presided over the estate. Origin of preside.
The title president is sometimes used by extension for leaders of other groups, including corporate entities and social groups. Etymologically, a president is one who presides (from Latin prae- before + sedere to sit; giving the term praeses). Originally, the term referred to the presiding officer of a ceremony or meeting (i.e., chairman), but today it most commonly refers to an executive official.