WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
inflammation of the brain usually caused by a virus; symptoms include headache and neck pain and drowsiness and nausea and fever (`phrenitis' is no longer in scientific use)
Word Usage
"For somebody who develops a severe, debilitating disease, such as encephalitis, which is a swelling and infection of the brain, that usually requires more supportive measures within a hospital."