A surgical bone rongeur isa heavy-duty, plier-like medical instrument used to bite, gnaw, or chip away small pieces of bone and tough fibrous tissue. 

Derived from the French word for "rodent" or "gnawer", it differs from a bone cutter (bone shear), which features flat, scissor-like blades designed to slice completely through bone structures or bisect them. Both instruments are indispensable in orthopedic, neurosurgical, spinal, and maxillofacial procedures to create surgical windows, reshape skeletal structures, or relieve neural pressure.