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

The industry is largely reactive rather than proactive. —Georgina Jedikovska, Interesting Engineering, 24 Mar. 2026

For decades, wildfires were considered a reactive emergency, but more disaster experts are looking for ways to apply proactive messaging, deployment and warning systems to fires — systems more akin to hurricane preparedness. —Grace Toohey, Los Angeles Times, 24 Mar. 2026

Watch for being overly reactive as the Gemini moon confronts Mars. —Usa Today, USA Today, 24 Mar. 2026

The agency said the facility contained about 440 pounds of highly reactive chemicals. —Arkansas Online, 21 Mar. 2026

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