hepatitis B

noun

: an acute or chronic hepatitis that is caused by a DNA virus (Orthohepadnavirus hominoidei of the family Hepadnaviridae), is marked chiefly by fatigue, fever, nausea, vomiting, abdominal pain, darkened urine, jaundice, and joint pain but may be asymptomatic, and is transmitted especially by contact with infected blood (as by transfusion or by sharing contaminated needles in illicit intravenous drug use) or by contact with other infected bodily fluids (such as semen)

Note: The acute form of hepatitis B, a mild illness lasting several weeks to months, may progress to long-term or chronic infection often leading to liver damage, liver failure, or liver cancer.

called also serum hepatitis

Examples of hepatitis B in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
On Monday, the state proposed a rule to remove requirements that children get vaccinated against chickenpox, hepatitis B, Haemophilus influenzae type B, and pneumococcal to enter school. Beth Mole, ArsTechnica, 26 Aug. 2026 The country saw similar declines for vaccines that protect against polio, hepatitis B, and diphtheria, tetanus and acellular pertussis. Jackie Flynn Mogensen, Scientific American, 24 Aug. 2026 Among the vaccines demoted to the latter two categories are those protecting against meningococcal disease, which can result in death within 24 hours of symptoms showing up, and hepatitis B, which can cause chronic liver disease. Chuka Onuh, Chicago Tribune, 20 Aug. 2026 The six vaccines no longer recommended to all children were for COVID-19, seasonal flu, hepatitis A, hepatitis B, respiratory syncytial virus (RSV), and rotavirus. Dominique Mosbergen, Time, 12 Aug. 2026 See All Example Sentences for hepatitis B

Word History

First Known Use

1971, in the meaning defined above

Time Traveler
The first known use of hepatitis B was in 1971

Browse Nearby Words

Cite this Entry

“Hepatitis B.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hepatitis%20B. Accessed 1 Sep. 2026.

Medical Definition

: an acute or chronic hepatitis that is caused by a double-stranded DNA virus (Orthohepadnavirus hominoidei of the family Hepadnaviridae), is marked chiefly by fatigue, fever, nausea, vomiting, abdominal pain, darkened urine, jaundice, and joint pain but may be asymptomatic, and is transmitted especially by contact with infected blood (as by transfusion or by sharing contaminated needles in illicit intravenous drug use) or by contact with other infected body fluids (such as semen)

Note: The acute form of hepatitis B, a mild illness lasting several weeks to months, may progress to long-term or chronic infection often leading to liver damage, liver failure, or liver cancer.

called also homologous serum hepatitis, homologous serum jaundice, serum hepatitis

More from Merriam-Webster on hepatitis B

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!