iodine

[ ahy-uh-dahyn, -din; in Chemistry also ahy-uh-deen ]

/ ˈaɪ əˌdaɪn, -dɪn; in Chemistry also ˈaɪ əˌdin /

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noun Chemistry.

a nonmetallic halogen element occurring at ordinary temperatures as a grayish-black crystalline solid that sublimes to a dense violet vapor when heated: used in medicine as an antiseptic. Symbol: I; atomic weight: 126.904; atomic number: 53; specific gravity: (solid) 4.93 at 20°C.

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Sometimes i·o·din

[ahy-uh-din]. /ˈaɪ ə dɪn/.

Origin of iodine

First recorded in 1814; from French iode + -ine² (def. 2); introduced by H. Davy. Ultimately from Greek īṓdēs, originally “rust-colored”, but by folk etymology taken as í(on) “violet” + -ōdēs noun suffix; see -ode¹

Words nearby iodine

iodic, iodic acid, iodide, iodimetry, iodinate, iodine, iodine 131, iodism, iodize, iodo-, iodoform

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use iodine in a sentence

In fact, the iodine was such an effective nucleator that the researchers had a difficult time scrubbing it away from the sides of the chamber for subsequent experiments, which required a completely clean environment.
Cloud-Making Aerosol Could Devastate Polar Sea Ice|Max Kozlov|February 23, 2021|Quanta Magazine
Walnut trees have a small amount of iodine in the nuts and in their sap.
Make your own maple syrup without harming the trees|By Tim MacWelch/Outdoor Life|February 7, 2021|Popular-Science
Salt enhanced with iodine is often our primary source of this essential nutrient.
Five myths about nutrition|Jessica Wilson|December 31, 2020|Washington Post
After reconstructing the supply chain that way, he tracked down the country’s salt producers to talk to them about iodine.
One man’s crusade to end a global scourge with better salt|Katie McLean|December 18, 2020|MIT Technology Review

It became a secondary priority because of the push with iodine.
One man’s crusade to end a global scourge with better salt|Katie McLean|December 18, 2020|MIT Technology Review
The website even sells iodine drops, called “Survival Shield,” at their official store.
Dear Moon Landing Deniers: Sorry I Called You Moon Landing Deniers|Olivia Nuzzi|July 29, 2014|DAILY BEAST
The sun was strangely warm on my wrists, or perhaps they were tingling from the potassium iodine.
Japan's Nuclear Ghost Towns|William T. Vollmann|May 2, 2011|DAILY BEAST
They said this phenomenon might have caused the level of iodine to rise before the tap water could reach the purifying plant.
Radiation in Tokyo's Tap Water|Lennox Samuels|March 23, 2011|DAILY BEAST
At Chernobyl, iodine fell on the grass, cows ate the grass, and people drank the milk.
California's Nuclear Freakout|Josh Dzieza, Tricia Romano|March 18, 2011|DAILY BEAST
Brenner said that distributing iodine in Japan is prudent, but probably unecessary.
California's Nuclear Freakout|Josh Dzieza, Tricia Romano|March 18, 2011|DAILY BEAST
This I attribute to the potash being in a little more caustic condition than when recrystallised with iodine.
Notes and Queries, Number 177, March 19, 1853|Various
Of the other substances, iodine is restricted exclusively to sea-plants, but to them it appears to be essential.
Elements of Agricultural Chemistry|Thomas Anderson
The calculation may be made exactly as in the case of the similar constant for iodine (p. 273).
The Elements of Qualitative Chemical Analysis, vol. 1, parts 1 and 2.|Julius Stieglitz
The tendency of iodine to form hypoiodous acid, iodates, etc., is not taken into consideration here and involves another relation.
The Elements of Qualitative Chemical Analysis, vol. 1, parts 1 and 2.|Julius Stieglitz
"Yes, 'tis his left hand he'd be using all the time when I'm not noticing him," said Kate, returning with the iodine.
The Boy Grew Older|Heywood Broun

British Dictionary definitions for iodine

iodine

/ (ˈaɪəˌdiːn) /

noun

a bluish-black element of the halogen group that sublimates into a violet irritating gas. Its compounds are used in medicine and photography and in dyes. The radioisotope iodine-131 (radioiodine), with a half-life of 8 days, is used in the diagnosis and treatment of thyroid disease. Symbol: I; atomic no: 53; atomic wt: 126.90447; valency: 1, 3, 5, or 7; relative density: 4.93; melting pt: 113.5°C; boiling pt: 184.35°C

Word Origin for iodine

C19: from French iode, from Greek iōdēs rust-coloured, but taken to mean violet-coloured, through a mistaken derivation from ion violet

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for iodine

iodine

[ ī′ə-dīn′ ]

A shiny, grayish-black element of the halogen group. It is corrosive and poisonous and occurs in very small amounts in nature except for seaweed, in which it is abundant. Iodine compounds are used in medicine, 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 Periodic Table.