thyroid

 
Pronunciation: /ˈθʌɪrɔɪd/

noun

  • 1 (also thyroid gland) a large ductless gland in the neck which secretes hormones regulating growth and development through the rate of metabolism: [as modifier]: thyroid function thyroid hormones
  • [mass noun] an extract prepared from the thyroid gland of animals and used in treating deficiency of thyroid hormones.
  • 2 (also thyroid cartilage) a large cartilage of the larynx, a projection of which forms the Adam’s apple in humans.

Origin:

early 18th century (as an adjective): from Greek (khondros) thureoeidēs 'shield-shaped (cartilage)', from thureos 'oblong shield'