underactive
adjective
un·der·ac·tive
ˌən-dər-ˈak-tiv 
: characterized by an abnormally low level of activity
an underactive thyroid gland
Examples of underactive in a Sentence
Recent Examples on the Web
Levothyroxine Levothyroxine is a hormone replacement for patients with underactive thyroid function, also called hypothyroidism.
—
Mira Miller, Verywell Health, 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
A number of factors can lead to appetite loss, including conditions such as cancer, an underactive thyroid, and depression.
—Laura Schober, Health, 21 Aug. 2025
An underactive thyroid gland can affect brain development for growing babies, according to Johns Hopkins medicine.
—Ishani Desai, Sacbee.com, 17 July 2025
See All Example Sentences for underactive
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.
Mira Miller, Verywell Health, 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
A number of factors can lead to appetite loss, including conditions such as cancer, an underactive thyroid, and depression.
—Laura Schober, Health, 21 Aug. 2025
An underactive thyroid gland can affect brain development for growing babies, according to Johns Hopkins medicine.
—Ishani Desai, Sacbee.com, 17 July 2025
See All Example Sentences for underactive
Cite this Entry
“Underactive.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/underactive. Accessed 9 Sep. 2025.
Copy CitationKids Definition
underactive
adjective
un·der·ac·tive
ˌən-də-ˈrak-tiv
: having an abnormally low level of activity
an underactive gland
Medical Definition
underactive
adjective
un·der·ac·tive
-ˈak-tiv
: characterized by an abnormally low level of activity
an underactive thyroid gland
Love words? Need even more definitions?
Merriam-Webster unabridged
Share