underactive
adjective
un·der·ac·tive ˌən-dər-ˈak-tiv 
: characterized by an abnormally low level of activity
an underactive thyroid gland
underactivity
ˌən-dər-ak-ˈti-və-tē
noun 
Example Sentences
Recent Examples on the Web In hypothyroidism, your thyroid gland is underactive, and your metabolism slows down, sometimes leaving you with chills. 
Julie Stewart, Men's Health, 29 June 2022 But in the case of an underactive thyroid, for instance, ongoing hormone-replacement therapy is necessary, and no amount of dieting, exercise, or stress management can take its place. Christine Byrne, Outside Online, 8 July 2021 To diagnose a potential problem with your thyroid, your doctor will likely order a blood test to examine the level of your thyroid-stimulating hormone, which can signal that your thyroid is overactive or underactive. Korin Miller, SELF, 6 Oct. 2021 Although people often associate underactive — longer and overstretched — muscles with urinary incontinence, experts emphasized that the overactive muscles, which are also weak and not coordinated, could be to blame. Washington Post, 12 Feb. 2021 Over time, the medication may not be enough to keep symptoms away, leading to issues that mimic that of an underactive thyroid. Mike Wehner, BGR, 30 Apr. 2021 The show pokes fun at some of quarantine’s biggest challenges, including overeating, TV binge-watching, hyperactive children, underactive spouses and loads of alcohol. Brad Rhines, NOLA.com, 5 Oct. 2020 An underactive thyroid can cause dry skin that can lead to itchy breasts, in addition to many other symptoms like fatigue, constipation, thinning hair, and a slower heart rate, the Mayo Clinic says. Korin Miller, SELF, 10 Aug. 2020 Other possible causes of diffuse telogen hair loss include an overactive or underactive thyroid, with normal hair growth restored once the hormonal abnormality is corrected. New York Times, 3 Feb. 2020 See More
Julie Stewart, Men's Health, 29 June 2022 But in the case of an underactive thyroid, for instance, ongoing hormone-replacement therapy is necessary, and no amount of dieting, exercise, or stress management can take its place. Christine Byrne, Outside Online, 8 July 2021 To diagnose a potential problem with your thyroid, your doctor will likely order a blood test to examine the level of your thyroid-stimulating hormone, which can signal that your thyroid is overactive or underactive. Korin Miller, SELF, 6 Oct. 2021 Although people often associate underactive — longer and overstretched — muscles with urinary incontinence, experts emphasized that the overactive muscles, which are also weak and not coordinated, could be to blame. Washington Post, 12 Feb. 2021 Over time, the medication may not be enough to keep symptoms away, leading to issues that mimic that of an underactive thyroid. Mike Wehner, BGR, 30 Apr. 2021 The show pokes fun at some of quarantine’s biggest challenges, including overeating, TV binge-watching, hyperactive children, underactive spouses and loads of alcohol. Brad Rhines, NOLA.com, 5 Oct. 2020 An underactive thyroid can cause dry skin that can lead to itchy breasts, in addition to many other symptoms like fatigue, constipation, thinning hair, and a slower heart rate, the Mayo Clinic says. Korin Miller, SELF, 10 Aug. 2020 Other possible causes of diffuse telogen hair loss include an overactive or underactive thyroid, with normal hair growth restored once the hormonal abnormality is corrected. New York Times, 3 Feb. 2020 See More Word History
First Known Use
1959, in the meaning defined above
Medical Definition
underactive
adjective
un·der·ac·tive -ˈak-tiv
: characterized by an abnormally low level of activity
an underactive thyroid gland