overactive

1 of 2

adjective

over·​ac·​tive ˌō-vər-ˈak-tiv How to pronounce overactive (audio)
Synonyms of overactivenext
: excessively or abnormally active
overactive glands
an overactive imagination
overactivity
ˌō-vər-ak-ˈti-və-tē How to pronounce overactive (audio)
noun

overactivity

2 of 2

noun

: excessive or abnormal activity

Synonyms of overactive

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Adjective

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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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
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 Studies show the drug works by affecting brain chemicals such as glutamate and dopamine to help calm the overactive signals in the brain linked to agitation. — Dr. Jennifer Miao, ABC News, 1 May 2026 Red or Dark Skin With an overactive thyroid, your circulation increases. — Brandi Jones, Health, 28 Apr. 2026 Thyroid dysfunction — whether overactive or underactive — also disrupts the hair growth cycle. — Ascend Agency, New York Daily News, 16 June 2026 See All Example Sentences for overactive

Word History

First Known Use

Adjective

1647, in the meaning defined above

Time Traveler
The first known use of overactive was in 1647

Rhymes for overactive

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Browse Nearby Words

overaction
overactive
overactivity
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Cite this Entry

“Overactive.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/overactive. Accessed 8 Jul. 2026.

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Kids Definition

overactive

adjective
over·​ac·​tive ˌō-və-ˈrak-tiv How to pronounce overactive (audio)
: very active and especially abnormally so
an overactive thyroid
overactivity
-rak-ˈtiv-ət-ē How to pronounce overactive (audio)
noun

Medical Definition

overactive

adjective
over·​ac·​tive ˌō-və-ˈrak-tiv How to pronounce overactive (audio)
: excessively or abnormally active
an overactive mind
overactive glands
overactivity
-ˌrak-ˈtiv-ət-ē How to pronounce overactive (audio)
noun
plural overactivities

More from Merriam-Webster on overactive

Nglish: Translation of overactive for Spanish Speakers

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