thyromegaly vs disease

thyromegaly and disease both are nouns.

Word	Noun	Adjective	Verb	Adverb
thyromegaly	Yes	No	No	No
disease	Yes	No	No	No

As nouns, disease is a hypernym of thyromegaly; that is, disease is a word with a broader meaning than thyromegaly:

thyromegaly: abnormally enlarged thyroid gland; can result from underproduction or overproduction of hormone or from a deficiency of iodine in the diet
disease: an impairment of health or a condition of abnormal functioning

thyromegaly (noun)	disease (noun)
abnormally enlarged thyroid gland; can result from underproduction or overproduction of hormone or from a deficiency of iodine in the diet	an impairment of health or a condition of abnormal functioning