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

• agitated
• excited
• feverish
• frenzied
• heated
• hectic
• hyperactive
• overwrought

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

Systemic medications, which impact the whole body and can be more effective than other treatments in tougher eczema cases, work internally to calm the overactive immune response that often drives the condition. —Lynya Floyd, Allure, 23 May 2025

Sepsis is caused by an overactive immune response to infection. —Michael L. Millenson, Forbes.com, 22 May 2025

Hypothyroidism is an underactive thyroid gland, and hyperthyroidism is an overactive thyroid gland. —Colleen Doherty, Verywell Health, 12 May 2025

How Allergies Can Lead to Dizziness Allergies are caused by your immune system having an overactive response to an allergen. —Lindsay Curtis, Health, 25 Apr. 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