iodine

noun, often attributive
io·​dine | \ ˈī-ə-ˌdīn How to pronounce iodine (audio) , -dᵊn, -ˌdēn \

Definition of iodine

1 : a nonmetallic halogen element that is an essential nutrient in the human diet and is used especially in medicine, photography, and analytical chemistry — see Chemical Elements Table
2 : a tincture of iodine used especially as a topical antiseptic

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Did You Know?

Iodine is a nonmetallic chemical element and the heaviest nonradioactive halogen. It is a very nearly black crystalline solid that can turn to a deep violet, irritating vapor. In nature it is never found uncombined, and occurs mostly in brines and seaweeds. Dietary iodine is essential for thyroid gland function, so table salt usually has potassium iodide added to prevent iodine deficiency. Elemental iodine is used in medicine, in synthesizing some organic chemicals, in manufacturing dyes, in analytical chemistry, and in photography. The radioactive isotope I-131, with an eight-day half-life, is very useful in medicine and other applications.

Examples of iodine in a Sentence

Recent Examples on the Web Never blend iodine and chorine for water disinfection. Popular Science, "Wood filters, hot rocks, and seven other ways to purify water in the wild," 2 Nov. 2020 Other stories about the sterilization of Native American women, noted in a 1976 federal report, and military testing of radioactive iodine on Alaska Natives have bred distrust. The Salt Lake Tribune, "Fast rollout of virus vaccine trials reveals distrust among Native Americans," 4 Jan. 2021 Bone broths are loaded with vital nutrients like calcium, iodine, and minerals and have been found to help support thyroid health. Anchorage Daily News, "Alaska’s commercial fishery managers appear to be spared big budget cuts next year," 29 Dec. 2020 Gray salt comes from certain coastal regions in France and is packed with minerals like iron, calcium, and natural iodine. Ana Sanchez, chicagotribune.com, "The best salt," 23 Dec. 2020 Altman brushed sterile aqueous iodine over her face and hair, rendering her first rusty red and then yellow. Slanierdarby, Longreads, "There She Goes: How to ‘Feminize’ a Face," 13 Nov. 2020 The toxicity and flavor of iodine can be a little problematic. Popular Science, "Wood filters, hot rocks, and seven other ways to purify water in the wild," 2 Nov. 2020 Some dentists have started using what’s known as a pre-procedural rinse—a mixture of diluted hydrogen peroxide or iodine known to kill off some of the microbial menagerie that thrives in your mouth and upper throat. Maya Wei-haas, National Geographic, "How to safely go to the dentist during the pandemic," 8 Sep. 2020 Instead, Ayyadurai argued that people should take vitamins A, C, and D—as well as iodine—to strengthen their immune systems against the virus. Timothy B. Lee, Ars Technica, "Shiva “Inventor of Email” Ayyadurai loses race for GOP Senate nod," 2 Sep. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'iodine.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of iodine

1814, in the meaning defined at sense 1

History and Etymology for iodine

French iode "iodine" (borrowed from Greek ioeidḗs "violet-colored," from íon "the color violet"—going back to *wion, akin to the source of Latin viola "the violet flower"— + -o-eidēs -oid entry 2) + -ine entry 2 (after chlorine, fluorine) — more at violet

Note: The French word iode was apparently introduced by the chemists Bernard Courtois (1777-1838) and Joseph Louis Gay-Lussac (1778-1850); cf. B. Courtois, "Découverte d'une substance nouvelle dans le Vareck," Annales de chimie, tome 88 (1813), p. 305: "La substance nouvelle, que depuis on a nommé iode à cause de la belle couleur violette de sa vapeur, a bien tout l'aspect d'un métal." ("The new substance, which since has been named iode because of the beautiful violet color of its vapor, has all the appearance of a metal.") Note that a borrowing from Greek ioeidḗs should properly have yielded ioïde in French rather than iode; the direct source of the latter may have been iṓdēs "rust-colored," a derivative of íos "rust, verdigris," taken erroneously to be a derivative of íon "the color violet."

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Statistics for iodine

Last Updated

8 Feb 2021

Cite this Entry

“Iodine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/iodine. Accessed 27 Feb. 2021.

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More Definitions for iodine

iodine

noun

English Language Learners Definition of iodine

: a chemical element that is used especially in medicine and photography

iodine

noun
io·​dine | \ ˈī-ə-ˌdīn How to pronounce iodine (audio) , -dᵊn \

Kids Definition of iodine

1 : a chemical element found in seawater and seaweeds and used especially in medicine and photography
2 : a solution of iodine in alcohol used to kill germs

iodine

noun, often attributive
io·​dine | \ ˈī-ə-ˌdīn How to pronounce iodine (audio) , -əd-ᵊn How to pronounce iodine (audio) , -ə-ˌdēn How to pronounce iodine (audio) \

Medical Definition of iodine

1 : a nonmetallic halogen element obtained usually as heavy shining blackish gray crystals and used especially in medicine (as in antisepsis and in the treatment of goiter and cretinism) and in photography and chemical analysis symbol I — see Chemical Elements Table
2 : a tincture of iodine used especially as a topical antiseptic

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More from Merriam-Webster on iodine

Nglish: Translation of iodine for Spanish Speakers

Britannica English: Translation of iodine for Arabic Speakers

Britannica.com: Encyclopedia article about iodine

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