thyroid

²thyroid

noun

Definition of THYROID

1

: a large bilobed endocrine gland of craniate vertebrates that arises as a median ventral outgrowth of the pharynx, lies in the anterior base of the neck or anterior ventral part of the thorax, is often accompanied by lateral accessory glands sometimes more or less fused with the main mass, and produces especially the hormones thyroxine and triiodothyronine—called also thyroid gland

2

: a preparation of the thyroid gland of various domesticated food animals (as pigs) containing approximately ¹⁄₁₀ percent of iodine combined in thyroxine and used in treating thyroid disorders—called also thyroid extract

Illustration of THYROID