HIV

noun

ˌāch-ˌī-ˈvē 

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

Since the program started, Sullivan said the team has mailed out around 750,000 HIV tests to households across the U.S. —Mary Kekatos, ABC News, 2 May 2025

Those products are used to treat nausea and vomiting caused by cancer chemotherapy and loss of appetite and weight loss in people with HIV/AIDS. —Ron Hurtibise, Sun Sentinel, 2 May 2025

This usually happens when a person’s immune system weakens, often due to certain health conditions or treatments, including cancer, HIV and organ transplantation, Eckardt said. —Michelle Marchante, Miami Herald, 1 May 2025

Plotkin added that vaccines being developed for infections that are incurable, like HIV, may also be at risk. —Berkeley Lovelace Jr., NBC news, 1 May 2025

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 (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