ENGLISH
REFERENCE

thyroid

n. · adj.
US //ˈθaɪɹɔɪd// UK //θˈaɪɹɔɪd// thy·roid
  1. 1 the gland (n.)
    B2 Upper Intermediate Medicine

    a small gland in the front of your neck that produces hormones to control your metabolism and energy levels.

    the thyroid gland, an endocrine gland located in the neck that regulates metabolic rate through the secretion of hormones.

    Example

    The doctor ordered a blood test to check if her thyroid was working properly.

    Example

    Patients with an overactive thyroid often experience rapid weight loss and increased heart rate due to the accelerated metabolic state.
    • thyroid gland
  2. 2 relating to the gland (adj.)
    C1 Advanced Technical Medicine

    relating to the thyroid gland or the hormones it makes.

    pertaining to the thyroid gland, its function, or its associated anatomical structures.

    Example

    She is taking thyroid medication to help with her energy levels.

    Example

    The surgeon carefully avoided the thyroid cartilage while performing the delicate procedure on the patient's throat.

Origin

Borrowed from New Latin thyreoīdēs, from Ancient Greek θῠρεοειδής (thŭreoeidḗs, “shield-shaped”), from θῠρεός (thŭreós, “an oblong shield”) + -ειδής (-eidḗs, “-form, -like”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Related words

Last updated June 20, 2026