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[ree-ak-tiv-i-tee] /ˌri ækˈtɪv ɪ ti/
the quality or condition of being reactive.
Chemistry. the relative capacity of an atom, molecule, or radical to undergo a chemical reaction with another atom, molecule, or compound.
Physics. a measure of the deviation from the condition at which a nuclear reactor is critical.
Immunology. the ability of an antigen to combine with an antibody.
1885-90; reactive + -ity
Related forms
hyperreactivity, noun Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
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Examples from the web for reactivity
  • The mutant proteins were then purified to ensure that reactivity and side effects of the vaccine were minimized.
  • And this, in turn, suggests that anxiety results from a learning disorder rather than a reactivity disorder.
  • The second requirement needs to be that the system has a negative reactivity coefficient.
  • Previous research indicates that oxytocin plays a role in regulating stress and fear reactivity.
  • The modern nuclear plant shuts down when it overheats as it is designed with a negative coefficient of reactivity.
  • It would be interesting to explore the boundary between simple chemical reactivity and primary awareness.
  • Yet this reactivity can also make them good sensors.
reactivity in Medicine

reactivity re·ac·tiv·i·ty (rē'āk-tĭv'ĭ-tē)

  1. The property of reacting.

  2. The process of reacting.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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