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.
“Right now we’re seeing reactive responses. OK, let’s throw up some sandbags and plywood.”
From Los Angeles Times ● Oct. 17, 2026
The meeting of water and plastic creates a third class of molecules called reactive oxygen species.
From Los Angeles Times ● Oct. 17, 2026
"It didn't affect me at all until I took the last reactive injection, which basically releases the eggs into position for extraction the next day."
From BBC ● Oct. 13, 2026
The material contains an unusual sulfide-to-sulfide bond that temporarily breaks when exposed to light, producing highly reactive sulfur species.
From Science Daily ● Oct. 4, 2026
He’d thought it was some property of the metal that it was reactive with skin, but he was the only one who had reacted to it.
From "Strange the Dreamer" by Laini Taylor
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Get a wordDefinitions 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.
