1
: either of two retroviruses (species Human immunodeficiency virus 1 and 2 of the genus Lentivirus) that infect and destroy helper T cells of the immune system and that when left untreated cause AIDS

Note: HIV retroviruses are transmitted through contact with blood, semen, rectal and vaginal fluids, or breast milk and typically cause flu-like symptoms during the acute phase of infection, but often cause few or no symptoms during the chronic phase of infection when treated with antiretroviral drugs.

… the longer people are infected with HIV and the more immune-deficient they become, the more readily they seem to pass HIV to others.Robert R. Redfield et al.
Years of careful research have proven beyond doubt that the HIV virus causes AIDS, that antiretroviral drug treatment saves lives, and that the drug nevirapine is safe and effective in preventing the spread of HIV from mothers to their babies.Richard Marlink et al.

called also AIDS virus, human immunodeficiency virus

compare hiv-1, hiv-2
2
: the infection or disease caused by HIV
Early symptoms of HIV develop in 50 to 90 percent of people who are infected, usually beginning two to four weeks after exposure. … Because the signs and symptoms of … HIV may be similar to other common illnesses, such as mononucleosis, most people do not initially realize that they have HIV.Paul E. Sax

Examples of HIV in a Sentence

Recent Examples on the Web And antiviral treatment has changed HIV from a death sentence in the early '80s to people with HIV now having a normal life expectancy. Dana Taylor, USA TODAY, 26 Sep. 2024 Back home, their research led them to realize that preventing the spread of HIV meant empowering women to protect themselves. Alex Knapp, Forbes, 25 Sep. 2024 In the interim, half of American hemophiliacs, and many others, were infected with HIV by blood transfusions, leading to more than 4,000 deaths. Pamela Paul, The Mercury News, 24 Sep. 2024 The first medication to treat HIV came from a Caribbean sea sponge. Benji Jones, Vox, 20 Sep. 2024 See all Example Sentences for HIV 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'HIV.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1986, in the meaning defined at sense 1

Time Traveler
The first known use of HIV was in 1986

Dictionary Entries Near HIV

Cite this Entry

“HIV.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/HIV. Accessed 8 Oct. 2024.

Kids Definition

: any of a group of viruses that infect and destroy helper T cells causing the marked reduction in their numbers that is diagnostic of AIDS

Medical Definition

1
: either of two retroviruses (species Human immunodeficiency virus 1 and 2 of the genus Lentivirus) that infect and destroy helper T cells of the immune system and that when left untreated cause AIDS

Note: HIV retroviruses are transmitted through contact with blood, semen, rectal and vaginal fluids, or breast milk and typically cause flu-like symptoms during the acute phase of infection, but often cause few or no symptoms during the chronic phase of infection when treated with antiretroviral drugs.

called also AIDS virus, human immunodeficiency virus

compare hiv-1, hiv-2
2
: the infection or disease caused by HIV
Last Updated: - Updated example sentences
Love words? Need even more definitions?

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