immune system

American  

noun

Anatomy.

• immune systems
  plural

1. a diffuse, complex network of interacting cells, cell products, and cell-forming tissues that protects the body from pathogens and other foreign substances, destroys infected and malignant cells, and removes cellular debris: the system includes the thymus, spleen, lymph nodes and lymph tissue, stem cells, white blood cells, antibodies, and lymphokines.

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immune system Scientific  

1. The body system in humans and other animals that protects the organism by distinguishing foreign tissue and neutralizing potentially pathogenic organisms or substances. The immune system includes organs such as the skin and mucous membranes, which provide an external barrier to infection, cells involved in the immune response, such as lymphocytes, and cell products such as lymphokines.

2. See also autoimmune disease immune response

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immune system Cultural  

1. The system in the body that works to ward off infection and disease. Central to this system are the white blood cells. Some white blood cells produce antibodies in response to specific antigens that may invade the body; others function as scavengers to fight infection by destroying bacteria and removing dead cells.

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Other Word Forms

Noun Inflected Forms

• immune systems
  plural

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Etymology

Origin of immune system

First recorded in 1960–65

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Example Sentences

See Examples For:

immune system

He was discharged with a complex postsurgery medication regimen to keep his immune system in check and prevent infection, one that had to be followed perfectly.

From Slate ● Oct. 16, 2026

The researchers also designed the particles to avoid being immediately destroyed by the immune system.

From Science Daily ● Oct. 7, 2026

Yet another field that may have caught the medicine committee's eye is that of adhesion receptors in the immune system, identified by US immunologist Timothy Springer.

From Barron's ● Oct. 5, 2026

Abogen said its lead drug has potential to transform the treatment landscape for patients with autoimmune diseases—those in which the body’s immune system attacks healthy cells instead of protecting them.

From The Wall Street Journal ● Oct. 2, 2026

As Ebola sweeps through you, your immune system fails, and you seem to lose your ability to respond to viral attack.

From "The Hot Zone" by Richard Preston

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