1The protrusion of abdominal organs through a congenital hernia, wound, or surgical incision in the abdominal wall; an instance or case of this.
2More fully "diaphragmatic eventration", "eventration of the diaphragm". A condition, usually congenital, in which part of the diaphragm is thin and lacks muscle, and lies much higher in the chest than is normal.
Late 18th century; earliest use found in Michael Underwood (1737–1820), man-midwife and surgeon. Apparently from French éventration the action of cutting into the belly or other body cavity of an animal or person, a condition of the diaphragm from éventrer to eviscerate + -ation.