immunodeficiency

noun

im·​mu·​no·​de·​fi·​cien·​cy ˌi-myə-nō-di-ˈfi-shən(t)-sē How to pronounce immunodeficiency (audio)
i-ˌmyü-nō-
: inability to produce a normal complement of antibodies or immunologically sensitized T cells especially in response to specific antigens

Examples of immunodeficiency 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.
Another is the contagion risk posed by having an unvaccinated child in a waiting room alongside infants and kids with immunodeficiencies. — Eric Boodman, STAT, 3 Sep. 2026 In the early 2000s, a retroviral vector was used to treat boys with a severe immunodeficiency, sometimes called bubble-boy disease. — William A. Haseltine, Forbes.com, 10 Aug. 2026 Plasma plays a key role in trauma care and in creating medications for people with immune deficiencies, bleeding disorders, and neurological diseases like primary immunodeficiency, hemophilia and Guillain-Barré syndrome. — Dave Oates, San Diego Union-Tribune, 28 Jan. 2026 Those include primary immunodeficiencies, such as CVID, that impair the body’s ability to fight off infections, as well as bleeding disorders like hemophilia and some types of cancer. — Chantelle Lee, Time, 15 Dec. 2025 See All Example Sentences for immunodeficiency

Word History

Etymology

immuno- + deficiency

First Known Use

1969, in the meaning defined above

Time Traveler
The first known use of immunodeficiency was in 1969

Browse Nearby Words

Cite this Entry

“Immunodeficiency.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/immunodeficiency. Accessed 26 Sep. 2026.

Kids Definition

immunodeficiency

noun
im·​mu·​no·​de·​fi·​cien·​cy -də-ˈfish-ən-sē How to pronounce immunodeficiency (audio)
: inability to produce the normal number of antibodies or T cells capable of acting in an immune system

Medical Definition

immunodeficiency

noun
im·​mu·​no·​de·​fi·​cien·​cy -di-ˈfish-ən-sē How to pronounce immunodeficiency (audio)
plural immunodeficiencies
: inability to produce a normal complement of antibodies or immunologically sensitized T cells especially in response to specific antigens see aids
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