reactive

[ree-ak-tiv]

adjective

1. tending to react.

2. pertaining to or characterized by reaction.

3. Electricity.,  pertaining to or characterized by reactance.

reactive

/ rɪˈæktɪv, ˌriːækˈtɪvɪtɪ /

adjective

1. readily partaking in chemical reactions

   sodium is a reactive metal

   free radicals are very reactive

2. of, concerned with, or having a reactance

3. responsive to stimulus

4. (of mental illnesses) precipitated by an external cause

   reactive depression

Other Word Forms

• reactively adverb
• reactiveness noun
• antireactive adjective
• hyperreactive adjective
• nonreactive adjective
• overreactive adjective
• unreactive adjective
• reactivity noun

Word History and Origins

Origin of reactive¹

First recorded in 1705–15; react + -ive

Example Sentences

Before treatment, the cells had been exposed to conditions that increased reactive oxygen species, which are molecules known to trigger inflammation and damage collagen.

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If you know you’re overly reactive to certain conversations, let your partner know beforehand so that they aren’t caught off guard in the moment.

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They found that paclitaxel, a commonly used chemotherapy drug, prompts immune cells to produce large amounts of reactive oxygen species, which are molecules that place cells under stress.

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Here, you try to be as proactive as possible, but often it’s reactive.

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Researchers at NYU Langone Health have identified how a specific form of cell death linked to the buildup of highly reactive molecules can slow the growth of lung tumors.

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Related Words

• conscious 
• delicate 
• emotional 
• hypersensitive 
• keen 
• nervous 
• perceptive 
• precise 
• receptive 
• responsive 
• susceptible 
• tense 
• touchy 
• tricky 
• unstable