encephalitis
noun
en·ceph·a·li·tis
in-ˌse-fə-ˈlī-təs 
plural encephalitides
in-ˌse-fə-ˈli-tə-ˌdēz
: inflammation of the brain that is caused especially by infection with a virus (such as herpes simplex or West Nile virus) or less commonly by bacterial or fungal infection or autoimmune reaction
Note: Encephalitis may be asymptomatic or present with mild to severe symptoms (such as fever, headache, confusion, seizures, or loss of consciousness) sometimes progressing to coma or death.
Examples of encephalitis in a Sentence
Recent Examples on the Web
Brain problems: Rare complications include cerebellar ataxia (trouble with coordination), encephalitis (brain swelling), or meningitis (infection of membranes surrounding the brain and spine).
—
Brandi Jones, Msn-Ed, Health, 18 Oct. 2024
Joe Casey, 54, is on a ventilator at Exeter Hospital, and has tested positive for eastern equine encephalitis (EEE), West Nile Virus, and St. Louis encephalitis — all mosquito-bourne illnesses.
—Cara Lynn Shultz, Peoplemag, 3 Sep. 2024
Two pools, comprising 46 mosquitoes from two ZIP codes, have also tested positive for the virus that causes St. Louis encephalitis.
—Chantelle Lee, TIME, 11 June 2024
About 1 in every 20 children will develop pneumonia, and others may develop a dangerous swelling in the brain called encephalitis.
—Deidre McPhillips and Jacqueline Howard, CNN, 2 Oct. 2024
See all Example Sentences for encephalitis 
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Brandi Jones, Msn-Ed, Health, 18 Oct. 2024
Joe Casey, 54, is on a ventilator at Exeter Hospital, and has tested positive for eastern equine encephalitis (EEE), West Nile Virus, and St. Louis encephalitis — all mosquito-bourne illnesses.
—Cara Lynn Shultz, Peoplemag, 3 Sep. 2024
Two pools, comprising 46 mosquitoes from two ZIP codes, have also tested positive for the virus that causes St. Louis encephalitis.
—Chantelle Lee, TIME, 11 June 2024
About 1 in every 20 children will develop pneumonia, and others may develop a dangerous swelling in the brain called encephalitis.
—Deidre McPhillips and Jacqueline Howard, CNN, 2 Oct. 2024
See all Example Sentences for encephalitis
Dictionary Entries Near encephalitis
Cite this Entry
“Encephalitis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/encephalitis. Accessed 10 Nov. 2024.
Copy CitationKids Definition
encephalitis
noun
en·ceph·a·li·tis
in-ˌsef-ə-ˈlīt-əs
(ˌ)en-
: inflammation of the brain
also
: a disease marked by encephalitis
Medical Definition
encephalitis
noun
en·ceph·a·li·tis
in-ˌsef-ə-ˈlīt-əs
plural encephalitides
-ˈlit-ə-ˌdēz
: inflammation of the brain that is caused especially by infection with a virus (such as herpes simplex, varicella zoster, or West Nile virus) or less commonly by bacterial or fungal infection or autoimmune reaction
Note: Encephalitis may be asymptomatic or present with mild to severe symptoms (such as fever, headache, confusion, seizures, or loss of consciousness) sometimes progressing to coma or death.
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