thyroid

thyroid — noun

1. The thyroid is a small organ near the front of your neck that releases hormones

1.nounB2
Definition

The thyroid is a small organ near the front of your neck that releases hormones to guide how your body grows and uses energy.

Example

Kenji's doctor ordered an ultrasound to check whether his thyroid was enlarged.

collocation: enlarged thyroid

An underactive thyroid can slow down your metabolism and make you feel tired.

collocation: underactive / overactive thyroid

Common collocations
  • thyroid gland
  • thyroid hormone
  • thyroid function
  • thyroid nodule
  • overactive thyroid
  • underactive thyroid
  • enlarged thyroid

Grammar Patterns

the thyroid

thyroid + noun (attributive)

Usage Note

Distinguish from parathyroid glands, which are four small glands located behind the thyroid that control calcium levels. The adjective form is used before a noun (e.g., "thyroid function").

Common Mistakes

She has a problem with her thyroyd.
She has a problem with her thyroid.
The correct spelling is thy-ROID, not thy-ROYD.

thyroid — adjective

Word family

  • thyroidal
    adjectiveC1

Synonym discussion

Sense: noun/1

While 'thyroid' names a specific organ, 'gland' is the broader category — a structure that releases substances into the body. For example, the body also has sweat glands and salivary glands, which do very different jobs. 'Hormone' refers to the chemical messengers the thyroid produces, not the organ itself. A learner would say 'The thyroid produces hormones that control metabolism,' not 'The hormone produces hormones.' Use 'thyroid' when referring to the organ itself; use 'gland' when comparing it to other organs of the same type; use 'hormone' only when discussing the substances it releases.

thyroid ↗glandhormone ↗

Common collocations

Nouns

Phrases

  • thyroid function test
  • thyroid hormone level
  • overactive thyroid
  • underactive thyroid

Prepositions

  • of the thyroid
  • in the thyroid

Etymology

GreekLatinEnglish

The word 'thyroid' comes from Greek 'thyreos' (shield) combined with '-eides' (shaped like), because the thyroid cartilage in the throat was thought to look like a shield. The term was first used in English in the 1600s to describe the cartilage, and later applied to the gland itself.