A rongeur is a strongly constructed instrument with a sharp-edged, scoop-shaped tip, used for gouging out bone. Rongeur is a French word that means rodent or 'gnawer'.
A rongeur can be used to open a window in bone, often in the skull. It is used in neurosurgery, podiatric surgery, and orthopedic surgery to expose areas for operation.
The Stille-Luer Horsley and Leksell rongeur point straight from the handle, while the duckbill points to the side.