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.

---

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

---

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.

---

Other Word Forms

Noun Inflected Forms

• immune systems
  plural

---

Etymology

Origin of immune system

First recorded in 1960–65

---

Example Sentences

See Examples For:

immune system

Melanoma tumors carry lots of mutations, giving the vaccine plenty of targets to train the immune system to recognize.

From The Wall Street Journal ● Oct. 24, 2026

"These particles are little magnets that attract the bacterial toxin, and they hijack the immune system, preventing it from clearing bacteria," said Kotsakis.

From Science Daily ● Oct. 23, 2026

It takes time for the immune system to be trained, and for Healy, that means the benefits of a therapeutic vaccine will come later.

From MarketWatch ● Oct. 23, 2026

It is personalised to each patient, using information from their own tumour to help train their immune system to recognise cancer cells and target them if they return.

From BBC ● Oct. 23, 2026

It occurs when an overactive immune system begins attacking the cells that create pigment, or color, in the skin.

From "How to Disappear Completely" by Ali Standish

Random Word

Spin the wheel and learn a new word!

---