Cerebrum: The largest part of the brain. It is divided into two hemispheres, or halves.
The word "cerebrum" is the Latin word for "brain." The Romans used the same word to refer to the "skull" (which houses the brain) and the "head" (which houses the skull). And in Rome "cerebrum" also meant "understanding" (and a fiery temper). The word "cerebrate", meaning "to use the mind or think", comes from the Latin "cerebrum."