tolerance

noun

tol·​er·​ance ˈtä-lə-rən(t)s How to pronounce tolerance (audio)
ˈtäl-rən(t)s
1
: capacity to endure pain or hardship : endurance, fortitude, stamina
2
a
: sympathy or indulgence for beliefs or practices differing from or conflicting with one's own
b
: the act of allowing something : toleration
3
: the allowable deviation from a standard
especially : the range of variation permitted in maintaining a specified dimension in machining a piece
4
a(1)
: the capacity of the body to endure or become less responsive to a substance (such as a drug) or a physiological insult especially with repeated use or exposure
developed a tolerance to painkillers
also : the immunological state marked by unresponsiveness to a specific antigen
(2)
: relative capacity of an organism to grow or thrive when subjected to an unfavorable environmental factor
b
: the maximum amount of a pesticide residue that may lawfully remain on or in food

Examples of tolerance in a Sentence

a tolerance for other lifestyles The plants have a high tolerance for heat. Some patients gradually develop a tolerance for the drug and need to be given a larger dose. Some patients develop greater tolerance for the drug's effects.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The trio had, in research dating back two decades, uncovered a key pathway the body uses to keep the immune system in check, called peripheral immune tolerance. Jessica Coacci, Fortune, 8 Oct. 2025 Before the trio of prize winners came along, researchers thought that such immune tolerance occurred centrally, in the thymus, the primary lymphoid organ that sits in the center of the chest. Beth Mole, ArsTechnica, 6 Oct. 2025 Their work on two key components of immune tolerance – regulatory T cells and the FOXP3 gene – transformed how researchers like me understand the immune system, opening new doors for treating autoimmune diseases and cancer. Aimee Pugh Bernard, The Conversation, 6 Oct. 2025 With a clearer picture of cash flow, an advisor can make investing recommendations based on your goals, risk tolerance and timeline. Kate Dore, Cfp®, Ea,kelli Grant, Cfp®, CNBC, 1 Oct. 2025 See All Example Sentences for tolerance

Word History

First Known Use

15th century, in the meaning defined at sense 1

Time Traveler
The first known use of tolerance was in the 15th century

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Cite this Entry

“Tolerance.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tolerance. Accessed 9 Oct. 2025.

Kids Definition

tolerance

noun
tol·​er·​ance ˈtäl(-ə)-rən(t)s How to pronounce tolerance (audio)
1
a
: ability to put up with something harmful or unpleasant
b
: the ability to adjust to a food or drug so that its effects are experienced less strongly
2
: sympathy for or acceptance of feelings, habits, or beliefs that are different from one's own

Medical Definition

tolerance

noun
tol·​er·​ance ˈtäl(-ə)-rən(t)s How to pronounce tolerance (audio)
1
: the capacity of the body to endure or become less responsive to a substance (as a drug) or a physiological insult especially with repeated use or exposure
developed a tolerance to painkillers
2
: the immunological state marked by unresponsiveness to a specific antigen

More from Merriam-Webster on tolerance

Last Updated: - Updated example sentences
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