Dictionary.net

In vet. surg. a term applied to cattle and sheep affected with a disease caused by the retention of food in the maniplus or third stomach, between the numerous plaints of which it is firmly impacted. When the food is of a narcotic character, or unusually dry, tough, or indigestible, the stomach cannot moisten and reduce it with sufficient rapidity; and as fresh quantities continue to be received, the organ becomes over-gorged, and ultimately paralyzed and affected with chronic inflammation. Over-ripe clover, vetches, or rye-grass are liable to produce the disease.