General English


  • noun a chemical element. It is essential to the body, especially to the functioning of the thyroid gland, and is found in seaweed.


  • A trace element required for health especially of the thyroid gland, now included in iodized salt but available particularly from shell fish, seawater fish and seaweed


  • chemical symbolI

Origin & History of “iodine”

Íon was the Greek word for ‘violet’ (indeed it is related to English violet). from it was derived the adjective iṓdēs ‘violet-coloured’, which was taken by the chemist Joseph Louis Gay-Lussac as the basis of iode, the French term for ‘iodine’ (iodine gives off a purple vapour when heated). The British chemist Sir Humphry Davy adopted it into English, adding the suffix -ine to produce iodine.