- any of several small oval glands usually lying near or embedded in the thyroid gland.
- any one of the small egg-shaped endocrine glands situated near or embedded within the thyroid gland: they secrete parathyroid hormone
- Any of usually four small kidney-shaped glands that lie in pairs near or within the posterior surface of the thyroid gland and secrete a hormone necessary for the metabolism of calcium and phosphorus.
- Any of four kidney-shaped glands located behind or within the thyroid gland of many vertebrate animals.♦ The parathyroid glands secrete parathyroid hormone, which regulates the amount of calcium in the blood.
A set of four small glands on the undersurface of the thyroid gland that function in the endocrine system. The parathyroid glands secrete a hormone that regulates the metabolism of calcium and phosphorus.