cerebrum vs cranium

cerebrum

noun
  • The principal and most anterior part of the brain in vertebrates, which is located in the front area of the skull and divided into two hemispheres, left and right, separated by a fissure. In humans it is the largest part of the brain and is responsible for the integration of complex sensory functions and the initiation and coordination of voluntary activity, and the higher mental functions such as consciousness, thought, reason, emotion, and memory. 

cranium

noun
  • That part of the skull consisting of the bones enclosing the brain, but not including the bones of the face or jaw. 

  • Synonym of skull. 

  • The upper portion of the skull, including the neurocranium and facial bones, but not including the jawbone (mandible). 

How often have the words cerebrum and cranium occurred in a corpus of books? (source: Google Ngram Viewer )