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

Thyroid dysfunction — whether overactive or underactive — also disrupts the hair growth cycle. — Ascend Agency, New York Daily News, 16 June 2026

Long-term use of medications like prednisone and conditions like overactive thyroid also raise risk in ways worth flagging with a doctor. — Allison Palmer updated June 3, Sacbee.com, 3 June 2026

The acid also blocks tyrosinase, an enzyme involved in melanin production that can become overactive due to the body’s inflammatory response during a shingles infection. — Alyssa Sparacino, Glamour, 29 May 2026

Thus, people who have overactive versions of PCSK9 have fewer LDL receptors and higher LDL levels in their blood. — Beth Mole, ArsTechnica, 28 May 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