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[uhn-der-ak-tiv] /ˌʌn dərˈæk tɪv/
insufficiently active:
an underactive thyroid gland.
Origin of underactive
1955-60; under- + active
Related forms
underactivity, underactiveness, noun Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for underactive
  • The technique excites nerve cells in a small area of the brain that is underactive in depressed patients.
  • They engineered cells to become either hyperactive or underactive in response to specific wavelengths of light.
  • Pale skin areas are due to too little melanin or underactive melanocytes.
  • The immune response may be overactive or underactive.
  • Unfortunately, about half of those with underactive thyroids do not know they have a definable and treatable problem.
  • With guided imagery, you create relaxing images in your mind hypothyroidism see underactive thyroid hysterectomy.
  • Sometimes, however, the thyroid can get out of balance-either becoming overactive or underactive.
British Dictionary definitions for underactive


(of the thyroid or adrenal glands) not functioning at full capacity
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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