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
The product could cause adverse health consequences—including life-threatening infections—in people with weakened immune systems.
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Jenna Anderson, Health, 12 Dec. 2025
Key Takeaways Elderberry may help support your immune system and shorten the duration of colds or ease symptoms.
—Morgan Pearson, Verywell Health, 12 Dec. 2025
Alcohol impairs the immune system through several mechanisms, said Ednie, including disrupting communication between immune cells and damaging the gut barrier — both of which can trigger widespread inflammation.
—Andrea Margolis, FOXNews.com, 11 Dec. 2025
Unlike lactose intolerance, which is a digestive issue, milk allergy involves the immune system mistakenly identifying milk proteins as harmful and triggering an allergic response.
—Associate News Editor, MSNBC Newsweek, 11 Dec. 2025
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Jenna Anderson, Health, 12 Dec. 2025
Key Takeaways Elderberry may help support your immune system and shorten the duration of colds or ease symptoms.
—Morgan Pearson, Verywell Health, 12 Dec. 2025
Alcohol impairs the immune system through several mechanisms, said Ednie, including disrupting communication between immune cells and damaging the gut barrier — both of which can trigger widespread inflammation.
—Andrea Margolis, FOXNews.com, 11 Dec. 2025
Unlike lactose intolerance, which is a digestive issue, milk allergy involves the immune system mistakenly identifying milk proteins as harmful and triggering an allergic response.
—Associate News Editor, MSNBC Newsweek, 11 Dec. 2025
See All Example Sentences for immune system
Cite this Entry
“Immune system.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/immune%20system. Accessed 19 Dec. 2025.
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