Definition of reactivity
: the quality or state of being reactive emotional reactivity chemical reactivity If the brain, responding to psychological stress, stimulates the release of cortisol and cortisol suppresses the reactivity of the immune system, then a dormant viral infection may well flare up, or a new one catch hold.— Matt Ridley Abnormal reactivity to light and abnormal pupillary size may be important clues to the presence of cranial injury in the setting of head trauma.— Bradford J. Shingleton
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Time Traveler for reactivity
The first known use of reactivity was in 1832
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