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iodine

[ ahy-uh-dahyn, -din; in Chemistry also ahy-uh-deen ]
/ ˈaɪ əˌdaɪn, -dɪn; in Chemistry also ˈaɪ əˌdin /

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-123, iodine-125, iodine 131, iodine-fast, iodine-induced hyperthyroidism
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for iodine

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

Medical definitions for iodine

iodine
[ ī′ə-dīn′, -dĭn, -dēn′ ]

n.

A poisonous halogen element having compounds used as germicides, antiseptics, and food supplements, with numerous radioactive isotopes, which are used in diagnosis and treatment of thyroid diseases and neuroendocrine tumors. Atomic number 53.
A liquid containing iodine dissolved in ethyl alcohol, used as an antiseptic for wounds.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for iodine

iodine
[ ī′ə-dīn′ ]

I

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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.