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

When expectations are unclear, conversations become reactive and decisions rarely stick. —Lorraine K. Lee, Forbes.com, 20 Jan. 2026

Around the world, immigration policy is evolving from a reactive system into a proactive economic lever. —CBS News, 20 Jan. 2026

This interface is in contact with lithium for the entire lifetime of the battery and lithium is extremely reactive. —Georgina Jedikovska, Interesting Engineering, 20 Jan. 2026

While 2025 also saw a record number of crypto seizures by law enforcement, Burns Koven says that government and industry responses are still fragmented and reactive. —Carlos Garcia, Fortune, 20 Jan. 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