underactive

[ uhn-der-ak-tiv ]

adjective

1. insufficiently active:

   an underactive thyroid gland.

underactive

/ ˌʌndərˈæktɪv /

adjective

1. (of the thyroid or adrenal glands) not functioning at full capacity

Other Words From

• under·ac·tivi·ty under·active·ness noun

Word History and Origins

Origin of underactive¹

First recorded in 1955–60; under- + active

Example Sentences

An underactive thyroid, known as hypothyroidism, is caused by an inadequate production of thyroid hormone.

From Project Gutenberg