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
The outcome is reactive leadership, as seen in organizations that prioritize efficiency over culture, only to face burnout and high turnover.
—
Dr. Adil Dalal, Forbes.com, 3 Sep. 2025
Thioesters and early chemistry Earlier efforts to attach amino acids to RNA had relied on highly reactive compounds that quickly degraded in water and caused amino acids to clump together rather than bind to RNA.
—Neetika Walter, Interesting Engineering, 29 Aug. 2025
The police chief highlights the department's high homicide clearance rate but stresses the importance of prevention over solely reactive policing.
—David Clarey, jsonline.com, 28 Aug. 2025
Cavefish cells produce lower levels of certain molecules called cytokines that promote inflammation, as well as lower levels of reactive oxygen species — tissue-damaging byproducts of the body’s metabolism that are often elevated in people with obesity or diabetes.
—ArsTechnica, 25 Aug. 2025
See All Example Sentences for reactive
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Dr. Adil Dalal, Forbes.com, 3 Sep. 2025
Thioesters and early chemistry Earlier efforts to attach amino acids to RNA had relied on highly reactive compounds that quickly degraded in water and caused amino acids to clump together rather than bind to RNA.
—Neetika Walter, Interesting Engineering, 29 Aug. 2025
The police chief highlights the department's high homicide clearance rate but stresses the importance of prevention over solely reactive policing.
—David Clarey, jsonline.com, 28 Aug. 2025
Cavefish cells produce lower levels of certain molecules called cytokines that promote inflammation, as well as lower levels of reactive oxygen species — tissue-damaging byproducts of the body’s metabolism that are often elevated in people with obesity or diabetes.
—ArsTechnica, 25 Aug. 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 5 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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