immune system

noun

: the bodily system that protects the body from foreign substances, cells, and tissues by producing the immune response and that includes especially the thymus, spleen, lymph nodes, special deposits of lymphoid tissue (as in the gastrointestinal tract and bone marrow), macrophages, lymphocytes including the B cells and T cells, and antibodies

Examples of immune system in a Sentence

Recent Examples on the Web

As research continues, there will develop a clearer understanding of how cannabis interacts with the immune system during viral infections. —Tribune Content Agency, The Mercury News, 15 Nov. 2024

Adequate sleep is essential for keeping your immune system strong. —Judy Koutsky, Forbes, 2 Nov. 2024

Guillain-Barré syndrome is a side effect that takes place when your immune system attacks healthy nerve cells, leading to muscle weakness and paralysis in some cases. —Gordon G. Chang, Newsweek, 31 Oct. 2024

In general, a lymph node is a checkpoint along the route of your lymphatic system, a part of your immune system that’s responsible for catching and filtering out foreign substances that could cause harm. —Erica Sloan, SELF, 30 Oct. 2024

Word History

First Known Use

circa 1919, in the meaning defined above

Kids Definition

immune system

noun

: the bodily system that protects the body from foreign substances, cells, and tissues by producing the immune response and that includes especially the thymus, spleen, lymph nodes, lymphocytes, and antibodies

Medical Definition

immune system

noun

: the bodily system that protects the body from foreign substances, cells, and tissues by producing the immune response and that includes especially the thymus, spleen, lymph nodes, special deposits of lymphoid tissue (as in the gastrointestinal tract and bone marrow), lymphocytes including the B cells and T cells, and antibodies