un·​re·​ac·​tive ˌən-rē-ˈak-tiv How to pronounce unreactive (audio)
: not tending to react : not reactive
pupils unreactive to light
chemically unreactive solvents

Examples of unreactive in a Sentence

Recent Examples on the Web And the mirrors of the JWST are gilded with gold, an element useful for its unreactive nature and ability to reflect infrared light (not to mention its popularity in jewelry). Sanjana Curtis, Scientific American, 12 Dec. 2022 In between is just a short, unreactive benzene ring. John Timmer, Ars Technica, 27 Apr. 2022 Surrounding this core is an intermediate unreactive layer, for example a zinc sulfide shell. Gabriel A. Silva, Forbes, 23 Sep. 2021 These are the types of lasers that are best suited to photonics applications that need to use inert materials—oxides are very unreactive—and need to be small. Chris Lee, Ars Technica, 1 June 2019 Although nitrogen is the most abundant element in air, the molecular form of nitrogen found there is largely unreactive. Diana Gitig, Ars Technica, 27 May 2018

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'unreactive.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1832, in the meaning defined above

Time Traveler
The first known use of unreactive was in 1832

Dictionary Entries Near unreactive

Cite this Entry

“Unreactive.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unreactive. Accessed 24 Feb. 2024.

Medical Definition


un·​re·​ac·​tive -rē-ˈak-tiv How to pronounce unreactive (audio)
: not reactive
pupils unreactive to light
an unreactive gas
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