reactive
Americanadjective
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tending to react.
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pertaining to or characterized by reaction.
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Electricity. pertaining to or characterized by reactance.
adjective
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readily partaking in chemical reactions
sodium is a reactive metal
free radicals are very reactive
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of, concerned with, or having a reactance
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responsive to stimulus
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(of mental illnesses) precipitated by an external cause
reactive depression
Other Word Forms
Etymology
Origin of reactive
Explanation
To be reactive is to be ready to react or respond to something else — as opposed to ready to act on one's own. A person who's reactive does things only in response to others. To react is to do something in response to something else. When someone pinches you, for example, you react. But if you're a reactive person, then you only react; you're always ready to react but not to act on your own. You're rather lifeless unless something or someone else causes you to do act. This is usually seen as a negative trait in people, unless you're talking about, say, firefighters or cops. We admire people who don't need prodding to get things done. Some chemicals are called reactive, too, because they react readily with other chemicals.
Vocabulary lists containing reactive
Chemical Reactions - Introductory
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Matter and Energy 2: Properties of Matter, Chemical Reactions, and Energy
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The State of the Union Address 2015
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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.
“Greenspan marked the beginning of a much more reactive Fed. He started the shift toward overprotecting markets,” said Ethan Harris, former chief economist at Bank of America Securities.
From MarketWatch • Jun. 22, 2026
For Croatia's second goal, however, this situational back five was disrupted, likely because England's players were too reactive to the movement of individual opposition players.
From BBC • Jun. 18, 2026
"We've converted vaccine development from being reactive to being future proof. Our vaccines will continue to provide protection against viruses even as they mutate into new strains," said Heeney.
From Science Daily • Jun. 5, 2026
“Crypto’s 24/7 structure, higher leverage, and more reactive retail base mean it often front-runs macro moves, both on the way down and in recovery,” says Zhang.
From The Wall Street Journal • Jun. 5, 2026
The chemosterilants of this group are alkylating agents, which are extremely reactive chemicals, capable of intense cell destruction, damage to chromosomes, and production of mutations.
From "Silent Spring" by Rachel Carson
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.
