noun (n)

• 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)(noun.state)

  Synonym:
  cephalitis, encephalitis
  

  source: wordnet30
• Inflammation of the brain, or of the meninges of the brain, attended with acute fever and delirium; -- called also cephalitis.(noun)

  source: webster1913