reactive

adjective

re·​ac·​tive rē-ˈak-tiv How to pronounce reactive (audio)
Synonyms of reactivenext
1
: of, relating to, or marked by reaction or reactance
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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Those efforts reflect a broader goal of shifting from reactive support to sustained community development. J.m. Banks march 31, Kansas City Star, 31 Mar. 2026 While their methods differed, all three manufacturers treated cooling not as a reactive response but as essential to their long-term operational resilience. Jasmin Malik Chua, Sourcing Journal, 26 Mar. 2026 Public debate is often fragmented and reactive. Julie Finch, Literary Hub, 25 Mar. 2026 As skin gets thinner, drier, and more reactive over time, a gentler approach becomes less of a preference and more of a necessity. Christa Joanna Lee, Allure, 25 Mar. 2026 See All Example Sentences for reactive

Word History

First Known Use

1717, in the meaning defined at sense 1

Time Traveler
The first known use of reactive was in 1717

Browse Nearby Words

Cite this Entry

“Reactive.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/reactive. Accessed 2 Apr. 2026.

Kids Definition

reactive

adjective
re·​ac·​tive rē-ˈak-tiv How to pronounce reactive (audio)
1
: of or relating to reaction
2
: reacting or tending to react
reactively adverb
reactiveness noun
reactivity noun

Medical Definition

reactive

adjective
re·​ac·​tive rē-ˈak-tiv How to pronounce reactive (audio)
1
a
: of, relating to, or marked by reaction
reactive symptoms
a reactive process
b
: capable of reacting chemically
highly reactive materials
2
a
: readily responsive to a stimulus
the skin of the geriatric is less reactive than that of younger personsLouis Tuft
b
: occurring as a result of stress or emotional upset especially from factors outside the organism
reactive depression

More from Merriam-Webster on reactive

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster