overactive

1 of 2

adjective

over·​ac·​tive ˌō-vər-ˈak-tiv 

: excessively or abnormally active

overactive glands

an overactive imagination

overactivity

ˌō-vər-ak-ˈti-və-tē 

noun

overactivity

2 of 2

noun

: excessive or abnormal activity

Synonyms of overactive

Adjective

• heated
• excited
• agitated
• hyperactive

Examples of overactive in a Sentence

Adjective

She has an overactive bladder.

His crazy ideas are products of an overactive imagination.

Recent Examples on the Web

Adjective

People with atopic dermatitis also have an overactive immune system, which can trigger inflammation. — Ayren Jackson-Cannady, Allure, 20 Aug. 2026

Psoriasis is a chronic disease in which the immune system becomes overactive, causing inflamed, scaly patches of skin. — Grace Gavilanes, PEOPLE, 18 Aug. 2026

Treatment options for p-aHUS can vary, but Chin-Hong said there are medications available for p-aHUS, called complement inhibitors, that target the overactive complement system. — Yi-Jin Yu, ABC News, 13 Aug. 2026

Bret is obsessed, but is his fixation on Robert the product of lust or an overactive imagination that can’t be fulfilled by his work on a novel titled Less Than Zero? — Daniel Fienberg, HollywoodReporter, 5 Aug. 2026

Word History

First Known Use

Adjective

1647, in the meaning defined above

Rhymes for overactive

• bioactive
• hyperactive
• interactive
• nonreactive
• psychoactive
• putrefactive
• retroactive
• unattractive
• unreactive
• vasoactive
• active
• tractive

Kids Definition

overactive

adjective

over·​ac·​tive ˌō-və-ˈrak-tiv 

: very active and especially abnormally so

an overactive thyroid

overactivity

-rak-ˈtiv-ət-ē 

noun

Medical Definition

overactive

adjective

over·​ac·​tive ˌō-və-ˈrak-tiv 

: excessively or abnormally active

an overactive mind

overactive glands

overactivity

-ˌrak-ˈtiv-ət-ē 

noun

plural overactivities