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.
A person's brain.
Used other than figuratively or idiomatically: see upper, storey.