AIDS

noun

ˈādz

: a disease of the human immune system that is characterized cytologically especially by reduction in the numbers of CD4-bearing helper T cells to 20 percent or less of normal thereby rendering the subject highly vulnerable to life-threatening conditions (such as Pneumocystis carinii pneumonia) and to some (such as Kaposi's sarcoma) that become life-threatening and that is caused by infection with HIV commonly transmitted in infected blood especially during illicit intravenous drug use and in bodily secretions (such as semen) during sexual intercourse

Word History

Etymology

acquired immunodeficiency syndrome

First Known Use

1982, in the meaning defined above

Time Traveler

The first known use of AIDS was in 1982

See more words from the same year

Cite this Entry

Style

“AIDS.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/AIDS. Accessed 29 May. 2023.

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Kids Definition

AIDS

noun

ˈādz

: a serious disease of the human immune system marked by destruction of a large proportion of the helper T cells in the body due to infection by the HIV virus commonly transmitted especially in blood and semen

Medical Definition

AIDS

noun

ˈādz

: a disease of the human immune system that is characterized cytologically especially by a reduction in the numbers of CD4-bearing helper T cells to 20 percent or less of normal thereby rendering the subject highly vulnerable to life-threatening conditions (as Pneumocystis carinii pneumonia) and to some that become life threatening (as Kaposi's sarcoma) and that is caused by infection with HIV commonly transmitted in infected blood especially during illicit intravenous drug use and in bodily secretions (as semen) during sexual intercourse

called also acquired immune deficiency syndrome, acquired immunodeficiency syndrome