1
: either of two retroviruses (Lentivirus humimdef1 and L. humimdef2) 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

see also 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
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.
Thousands of Floridians who rely on ADAP to access HIV medication have been cut off since March 1. Ana Goñi-Lessan, Sun Sentinel, 12 Mar. 2026 The Florida Senate has unanimously approved money to help bridge a funding gap in a state program that provides life-saving HIV/AIDS medication andpayment assistance to nearly 30,000 low-income residents. Jeffrey Schweers, The Orlando Sentinel, 11 Mar. 2026 A week after Florida cut nearly 12,000 people off the state program providing affordable access to life-saving HIV/AIDS medication, state senators are making a last-minute move to fund the program in full for the next few months. Romy Ellenbogen, Miami Herald, 10 Mar. 2026 In Florida, 16,000 people just lost their coverage for HIV treatment. Marc Malkin, Variety, 10 Mar. 2026 See All Example Sentences for HIV

Word History

First Known Use

1986, in the meaning defined at sense 1

Time Traveler
The first known use of HIV was in 1986

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Cite this Entry

“HIV.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/HIV. Accessed 15 Mar. 2026.

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 (Lentivirus humimdef1 and L. humimdef2) 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

see also hiv-1, hiv-2
2
: the infection or disease caused by HIV
Last Updated: - Updated example sentences
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