reactive

adjective

re·​ac·​tive rē-ˈak-tiv 

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

Fractional works best when priorities are clear, communication is streamlined and the leader prioritizes strategic over reactive work. —Kenzie Biggins, Forbes.com, 24 July 2025

Hydrogen peroxide forms as a byproduct when energetic particles break apart water molecules, leading to the recombination of OH radicals — highly reactive molecules with unpaired electrons. —Victoria Corless, Space.com, 23 July 2025

Known for their bold, occasionally reactive behavior—especially when confronted by unfamiliar, larger breeds—this group appeared to stand their ground. —Melissa Fleur Afshar, MSNBC Newsweek, 23 July 2025

When used consistently, this language shifts culture from reactive responsiveness to strategic intentionality, normalizing deliberate choice-making in high-pressure environments and reinforcing that thoughtful limits enable meaningful impact. —Matt Emma, USA Today, 18 July 2025

Word History

First Known Use

1717, in the meaning defined at sense 1

Phrases Containing reactive

• C-reactive protein
• hyper-reactive
• reactive arthritis

Rhymes for reactive

• attractive
• contractive
• extractive
• inactive
• proactive
• refractive
• subtractive
• active
• tractive
• bioactive
• hyperactive
• interactive

Kids Definition

reactive

adjective

re·​ac·​tive rē-ˈak-tiv 

1

: of or relating to reaction

2

: reacting or tending to react

reactively adverb

reactiveness noun

reactivity

(ˌ)rē-ˌak-ˈtiv-ət-ē 

noun

Medical Definition

reactive

adjective

re·​ac·​tive rē-ˈak-tiv 

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 persons

—Louis Tuft

b

: occurring as a result of stress or emotional upset especially from factors outside the organism

reactive depression