reactivity
Americannoun
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the quality or condition of being reactive.
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Chemistry. the relative capacity of an atom, molecule, or radical to undergo a chemical reaction with another atom, molecule, or compound.
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Physics. a measure of the deviation from the condition at which a nuclear reactor is critical.
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Immunology. the ability of an antigen to combine with an antibody.
Other Word Forms
Etymology
Origin of reactivity
Vocabulary lists containing reactivity
Structure and Properties of Matter - Middle School
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Structure and Properties of Matter - Introductory
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Structure and Properties of Matter - High School
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
“Because we lose the ability to exert force quickly as we get older. Plyometrics — involving motor control, coordination, agility and reactivity — trains quick responses.”
From Los Angeles Times ● Aug. 18, 2026
The study found that the change in reporting dramatically reduced investors’ reactivity to market volatility, and a corresponding increase in their willingness to invest in riskier funds.
From MarketWatch ● May 2, 2026
"Also, prolonged vibration changes the reactivity of the neuromuscular spindles and alters the signal sent to the brain."
From Science Daily ● Jan. 8, 2026
Paris police chief Patrice Faure paid tribute to "the reactivity and the mobilisation" of the investigators that led to the arrest of the suspect.
From Barron's ● Dec. 27, 2025
Too much reactivity and we would spontaneously combust.
From "The Gene" by Siddhartha Mukherjee
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
