encephalitis(n = noun.state) cephalitis, phrenitis - 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);
is a kind of inflammation, redness, rubor
has particulars: acute hemorrhagic encephalitis, equine encephalitis, equine encephalomyelitis, acute inclusion body encephalitis, herpes encephalitis, herpes simplex encephalitis, leukoencephalitis, cerebromeningitis, encephalomeningitis, meningoencephalitis, panencephalitis, encephalitis lethargica, epidemic encephalitis, lethargic encephalitis, sleeping sickness, sleepy sickness, west nile encephalitis

   Inflammation of the brain. [1913 Webster]

encephalitis, n. inflammation of the brain.

Idiom:
encephalitis lethargica an infectious encephalitis caused by a virus, with headache and drowsiness leading to coma; sleepy sickness.

Derivative:
encephalitic adj.

acute hemorrhagic encephalitis, acute inclusion body encephalitis, bovine spongiform encephalitis, dawson's encephalitis, encephalitis lethargica, epidemic encephalitis, equine encephalitis, herpes encephalitis, herpes simplex encephalitis, inclusion body encephalitis, lethargic encephalitis, subacute inclusion body encephalitis, van bogaert encephalitis, west nile encephalitis, west nile encephalitis virus