overactive
adjective
over·ac·tive
ˌō-vər-ˈak-tiv 
: excessively or abnormally active
overactive glands
an overactive imagination
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
Inflammatory Skin Conditions Inflammatory skin conditions like eczema (atopic dermatitis) and psoriasis develop due to an overactive immune system.
—
Lindsay Curtis, Health, 4 Sep. 2025
The thyroid then releases thyroid hormone into the blood, causing the symptoms of an overactive thyroid gland or decreased thyroid hormone production as a result.
—Alyce Collins, MSNBC Newsweek, 25 Aug. 2025
This is important because hair loss can often be a sign of thyroid problems; both an underactive and an overactive thyroid can disrupt hair growth, resulting in hair thinning or shedding.
—Varsha Patel, Refinery29, 21 Aug. 2025
Therapeutic Botox – used for conditions that include muscle spasticity, migraines, overactive bladders, certain eye conditions and excessive sweating – brought in $3.3 billion for AbbVie last year, with sales of cosmetic Botox, often used to smooth facial wrinkles, generating $2.72 billion.
—Kara Fox, CNN Money, 14 Aug. 2025
See All Example Sentences for overactive
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Lindsay Curtis, Health, 4 Sep. 2025
The thyroid then releases thyroid hormone into the blood, causing the symptoms of an overactive thyroid gland or decreased thyroid hormone production as a result.
—Alyce Collins, MSNBC Newsweek, 25 Aug. 2025
This is important because hair loss can often be a sign of thyroid problems; both an underactive and an overactive thyroid can disrupt hair growth, resulting in hair thinning or shedding.
—Varsha Patel, Refinery29, 21 Aug. 2025
Therapeutic Botox – used for conditions that include muscle spasticity, migraines, overactive bladders, certain eye conditions and excessive sweating – brought in $3.3 billion for AbbVie last year, with sales of cosmetic Botox, often used to smooth facial wrinkles, generating $2.72 billion.
—Kara Fox, CNN Money, 14 Aug. 2025
See All Example Sentences for overactive
Cite this Entry
“Overactive.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/overactive. Accessed 9 Sep. 2025.
Copy CitationKids Definition
overactive
adjective
over·ac·tive
ˌō-və-ˈrak-tiv
: very active and especially abnormally so
an overactive thyroid
Medical Definition
overactive
adjective
over·ac·tive
ˌō-və-ˈrak-tiv
: excessively or abnormally active
an overactive mind
overactive glands
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