HIV

noun

ˌāch-ˌī-ˈvē 

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

The program is one of several that Mama’s Kitchen offers for San Diego residents with HIV, cancer, congestive heart failure, type 2 diabetes, chronic kidney disease and other critical illnesses. —Linda McIntosh, San Diego Union-Tribune, 19 Feb. 2026

Johneri'o Scott has been living with HIV for 10 years. —Daniel Wilkerson, CBS News, 18 Feb. 2026

He is credited with being a pioneer in using the fashion platform to address the HIV/AIDS crisis in the 1980s and more recently founded the Mental Health Coalition in 2020, when the mental health crisis was exacerbated amid the COVID-19 pandemic. —Kimberly Nordyke, HollywoodReporter, 17 Feb. 2026

In 2025, the American Civil Liberties Union of Idaho sued over parts of new laws, one creating state-level immigration crimes and a second preventing immigrants from using public services such as receiving HIV medication. —Idaho Statesman, 17 Feb. 2026

Word History

First Known Use

1986, in the meaning defined at sense 1

Phrases Containing HIV

• anti-HIV

Kids Definition

HIV

noun

ˌāch-ˌī-ˈvē 

: 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

HIV

noun

ˌā-ˌchī-ˈvē 

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