overactive

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

Synonyms of overactive

• heated
• excited
• agitated
• hyperactive

Examples of overactive in a Sentence

She has an overactive bladder.

His crazy ideas are products of an overactive imagination.

Recent Examples on the Web

New drugs to treat alopecia areata called JAK inhibitors were approved in just the last few years, which target the part of the immune system that has become overactive and attacks the hair follicles. —Sydney Lupkin, NPR, 23 Nov. 2025

Our spy senses are overactive, leading to paranoia. —Lisa Stardust, Refinery29, 6 Nov. 2025

By inhibiting calcineurin, voclosporin reduces the overactive immune response that drives lupus nephritis. —Robert Alexander, MSNBC Newsweek, 5 Nov. 2025

Our amygdala is overactive, our nervous systems are fried and our dopamine cycles are hijacked by short-term stimuli. —Chris Schembra, Rolling Stone, 22 Oct. 2025

Word History

First Known Use

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