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

Four add-ons—acupuncture, intralipid infusion (fat injections intended to regulate the immune system) and platelet-rich-plasma (PRP), or blood injections, in the uterus and ovaries—had either mixed evidence or low quality data backing them up. — Jackie Flynn Mogensen, Scientific American, 30 Sep. 2026

Immunology is the study of the body’s immune system and immunotherapy develops treatments that help the immune system fight diseases more effectively. — Tarini Mehta, Sacbee.com, 25 Sep. 2026

Taylor said research shows some patients who become gravely ill have compromised immune systems. — Susanne Rust follow, Los Angeles Times, 24 Sep. 2026

Transposable elements are linked to the evolution of animal eyes as well as the adaptive immune system in jawed vertebrates. — Jake Buehler, Quanta Magazine, 21 Sep. 2026

Word History

First Known Use

1899, 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