goitre vs thyroid gland

goitre

noun
  • An enlargement of the front and sides of the neck caused by inflammation of the thyroid gland. 

thyroid gland

noun
  • A large butterfly-shaped endocrine gland situated on the front of the neck that produces various hormones. 

How often have the words goitre and thyroid gland occurred in a corpus of books? (source: Google Ngram Viewer )