If you need to define a word in your paper, the definition usually comes from a glossary in the back of a book. To properly attribute this definition you will need to cite it according to the American Psychological Association (APA) style guidelines.
Encephalitis is inflammation of the brain tissue. It's most often caused by viral infections. In some cases, bacterial infections can also cause encephalitis.
Encephalitis means inflammation of the brain. This inflammation usually is triggered by a viral infection, although sometimes it can be caused by a bacterial infection of the brain, such as Lyme disease. In some cases, symptoms are caused by direct infection of the brain.