im·​mu·​no·​de·​fi·​cien·​cy | \ ˌi-myə-nō-di-ˈfi-shən(t)-sē How to pronounce immunodeficiency (audio) , i-ˌmyü-nō-\

Definition of immunodeficiency

: inability to produce a normal complement of antibodies or immunologically sensitized T cells especially in response to specific antigens

Keep scrolling for more

Other Words from immunodeficiency

immunodeficient \ ˌi-​myə-​nō-​di-​ˈfi-​shənt How to pronounce immunodeficient (audio) , i-​ˌmyü-​nō-​ \ adjective

Examples of immunodeficiency in a Sentence

Recent Examples on the Web

Valid medical reasons include when a child is undergoing chemotherapy, has a gelatin allergy or suffers from a severe immunodeficiency disorder, Governing magazine reports. NBC News, "Jessica Biel denies she's anti-vaccination after lobbying against California bill," 13 June 2019 People who are sick, suffer from immunodeficiency disorders or those with open wounds should not go into the river. Taryn Luna, sacbee, "E. coli levels drop at popular Sacramento beach | The Sacramento Bee," 21 Apr. 2018 Other people might experience this due to having a primary immunodeficiency disorder (i.e., a genetic predisposition for a weak immune system), according to the Mayo Clinic. Korin Miller, SELF, "What Does It Mean If You Get Every Single Cold Going Around the Office?," 2 Mar. 2018 Plagued with chronic respiratory infections as a child, she was diagnosed at age 4 with primary immunodeficiency, a disorder that weakens the immune system. Candace Jordan,, "Children's Ball raises record-breaking $3.75 million for pediatric research," 19 Dec. 2017 Consider feline immunodeficiency virus, which attacks cats’ immune systems and has a survival rate of 80% four to six years postinfection. Matthew R. Bailey, WSJ, "Love Your Dog, Support Animal Research," 17 Sep. 2017 The danger posed by serious catfights comes from the fact that deep wounds are one of the principal ways that feline leukemia and immunodeficiency disease are transmitted. Kwame Anthony Appiah, New York Times, "Can My Cat Go Out if He Bullies Other Cats?," 11 Oct. 2017 Cats living with feline immunodeficiency virus (FIV) often get overlooked at shelters. Nikki Delamotte,, "Meet a special group of cats from Cleveland's Tails from the City (photos, video)," 8 Sep. 2017 That caution arises from an incident in the late 2000s when several people developed a leukemia-like condition about 10 years after receiving an older form of gene therapy for an immunodeficiency disease. Joseph Walker, WSJ, "FDA Panel Votes Unanimously to Support Leukemia Gene-Therapy Treatment," 12 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'immunodeficiency.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of immunodeficiency

1969, in the meaning defined above

Keep scrolling for more

Learn More about immunodeficiency

Statistics for immunodeficiency

Look-up Popularity

Time Traveler for immunodeficiency

The first known use of immunodeficiency was in 1969

See more words from the same year

Keep scrolling for more

More Definitions for immunodeficiency



English Language Learners Definition of immunodeficiency

medical : a condition in which your body cannot produce enough of the substances or cells that it would normally produce to fight infection


im·​mu·​no·​de·​fi·​cien·​cy | \ -di-ˈfish-ən-sē How to pronounce immunodeficiency (audio) \
plural immunodeficiencies

Medical Definition of immunodeficiency

: inability to produce a normal complement of antibodies or immunologically sensitized T cells especially in response to specific antigens — see aids

Other Words from immunodeficiency

immunodeficient \ -​ənt How to pronounce immunodeficient (audio) \ adjective

More from Merriam-Webster on immunodeficiency

Nglish: Translation of immunodeficiency for Spanish Speakers

Comments on immunodeficiency

What made you want to look up immunodeficiency? Please tell us where you read or heard it (including the quote, if possible).


to move or obtain by small maneuvers

Get Word of the Day daily email!

Test Your Vocabulary

Summer 2019 Words of the Day Quiz

  • a-bowl-of-peach-sorbet-with-cut-peaches-next-to-it
  • Which is a synonym of desideratum?
Spell It

Can you spell these 10 commonly misspelled words?


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!