reactive
adjective
re·ac·tive
rē-ˈak-tiv 
2
a
: readily responsive to a stimulus
b
: occurring as a result of stress or emotional upset
reactive depression
reactively
adverb
reactiveness
noun
Examples of reactive in a Sentence
The government's response to the problem was reactive rather than proactive.
Recent Examples on the Web
Today, an era is beginning where AI agents are no longer simply reactive tools, but proactive colleagues.
—
Gaurav Aggarwal, Forbes.com, 17 Sep. 2025
Microbes unlock inert nitrogen gas and convert it into reactive forms of nitrogen, such as nitrate and ammonia, that plants and other organisms can use.
—Katherine Bourzac, Quanta Magazine, 15 Sep. 2025
With wildfire risk showing no signs of slowing down, a realignment of disaster management that prioritizes proactive measures rather than reactive ones must pave the way forward.
—Karen Collins, San Diego Union-Tribune, 15 Sep. 2025
Pay Attention to Subtle Cues The source of a dog’s trigger may not be fully understood, but an owner needs to pay attention and understand when and how their dog is activated, especially in reactive dogs.
—Madison Dapcevich, Outside, 15 Sep. 2025
See All Example Sentences for reactive
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Gaurav Aggarwal, Forbes.com, 17 Sep. 2025
Microbes unlock inert nitrogen gas and convert it into reactive forms of nitrogen, such as nitrate and ammonia, that plants and other organisms can use.
—Katherine Bourzac, Quanta Magazine, 15 Sep. 2025
With wildfire risk showing no signs of slowing down, a realignment of disaster management that prioritizes proactive measures rather than reactive ones must pave the way forward.
—Karen Collins, San Diego Union-Tribune, 15 Sep. 2025
Pay Attention to Subtle Cues The source of a dog’s trigger may not be fully understood, but an owner needs to pay attention and understand when and how their dog is activated, especially in reactive dogs.
—Madison Dapcevich, Outside, 15 Sep. 2025
See All Example Sentences for reactive
Cite this Entry
“Reactive.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/reactive. Accessed 19 Sep. 2025.
Copy CitationKids Definition
reactive
adjective
re·ac·tive
rē-ˈak-tiv
1
: of or relating to reaction
2
: reacting or tending to react
Medical Definition
reactive
adjective
re·ac·tive
rē-ˈak-tiv
1
2
a
: readily responsive to a stimulus
the skin of the geriatric is less reactive than that of younger persons—Louis Tuft
Louis Tuft
b
: occurring as a result of stress or emotional upset especially from factors outside the organism
reactive depression
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