What is the definition or description of: basilar skull fracture?

Fractured skull: A basilar skull fracture is a fracture or break in the bone at the bottom of the skull under the brain. It can be at the front of the head and involve the sinus cavities and orbits, the area in front and next to the ear and the area behind the ear. The fracture is often associated with bilateral "black eyes" and bruising behind the ear and may be associated with spinal fluid leak

Not common: A basilar skull fracture (or basal skull fracture) is a fracture of the base of the skull, typically involving the temporal bone, occipital bone, sphenoid bone, and/or ethmoid bone. This type of fracture is rare, occurring as the only fracture in just 4% of severe head injury patients.