Ileus \Il"e*us\, n. [NL., fr. Gr. ?, ?, fr. ? to roll up.] (Med.) A morbid condition due to intestinal obstruction. It is characterized by complete constipation, with griping pains in the abdomen, which is greatly distended, and in the later stages by vomiting of fecal matter. Called also {ileac, or iliac, passion}.