Definition of "iodine" []

• A lustrous, grayish-black, corrosive, poisonous halogen element having radioactive isotopes, especially I 131, used as a medical tracer and in thyroid disease diagnosis and therapy. Iodine compounds are used as germicides, antiseptics, and dyes. Atomic number 53; atomic weight 126.9045; melting point 113.5°C; boiling point 184.35°C; specific gravity (solid, at 20°C) 4.93; valence 1, 3, 5, 7. See Table at element. (noun)
• An antiseptic preparation containing iodine in solution, used to treat wounds. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Not surprisingly, the word violet is derived from the flower of the same name via the French violette or viola, and is cognate with the Greek ion, from which the word iodine is derived."
• "Here is a substance which we call iodine, and I am about to submit this solid body to the same kind of condition as regards heat that I did the water and the ether [putting a few grains of iodine into a hot glass globe, which immediately became filled with the violet vapor], and you see the same kind of change produced."
• "The herbal is rich in iodine compounds that stimulate thyroid gland functions."