Medical Dictionary

underactive

adj un·der·ac·tive \-ˈak-tiv\

Medical Definition of UNDERACTIVE

:  characterized by an abnormally low level of activity <an underactive thyroid gland>
un·der·ac·tiv·i·ty \-ak-ˈtiv-ət-ē\ noun, plural un·der·ac·tiv·i·ties

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