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

This would lessen the need of annual flu shots to boost the immune system before seasonal cases surge. —Lauren J. Young, Scientific American, 1 May 2025

Mushroom coffee is said to promote better sleep and boost the immune system, among other benefits. —Angelica Stabile, FOXNews.com, 1 May 2025

Researchers at Mass General Brigham, in affiliation with Harvard Medical School, found that the immune system influences stress and fear behaviors by altering how brain cells communicate. —Benjamin Adams, Forbes.com, 30 Apr. 2025

Those most at risk for contracting measles are the unvaccinated and those who are receiving treatment or have conditions that impact the immune system. —Lillie Davidson, Fort Worth Star-Telegram, 30 Apr. 2025

Word History

First Known Use

circa 1919, in the meaning defined above

Rhymes for immune system

• cryptosystem
• ecosystem
• intersystem
• multisystem
• photosystem
• subsystem

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