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

However, individuals with weakened immune systems, premature infants, or critically ill patients may be at higher risk for serious infections and should only use probiotics under close supervision of their healthcare provider. —Elizabeth Barnes, Verywell Health, 5 Nov. 2024

No illnesses have been reported so far, however, Listeria infections can be dangerous, particularly for older people, young kids, people with weakened immune systems, and pregnant people. —Julia Landwehr, Health, 5 Nov. 2024

For most people, regularly getting eight hours of sleep boosts memory retention, enhances concentration, augments creativity, stabilizes emotions, strengthens the immune system, enhances athletic performance, and staves off deadly ailments like cancers and heart disease. —Dr. Peter H. Diamandis, TIME, 4 Nov. 2024

Listeria is a particularly resilient bacterium that can cause severe health complications, particularly for pregnant women, the elderly, newborns and those with weakened immune systems. —David Faris, Newsweek, 3 Nov. 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