Definition of iodine
1 : a nonmetallic halogen element obtained usually as heavy shining blackish-gray crystals and used especially in medicine, photography, and analysis — see element table
2 : a tincture of iodine used especially as a topical antiseptic
Recent Examples of iodine from the Web
The revamp, which also includes selling more Maggi products with extra iodine, iron and vitamin A, will probably spur demand, England said.
Iodine, a startup co-founded by former WIRED executive editor Thomas Goetz, crowdsources patient reviews, and presents them alongside clinical trial data and input from pharmacists.
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.
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.
Origin and Etymology of iodine
French iode, from Greek ioeidēs violet colored, from ion violet
First Known Use: 1814See Words from the same year
IODINE Defined for English Language Learners
Definition of iodine for English Language Learners
: a chemical element that is used especially in medicine and photography
IODINE Defined for Kids
Definition of iodine for Students
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
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 element table
2: a tincture of iodine used especially as a topical antiseptic
Seen and Heard
What made you want to look up iodine? Please tell us where you read or heard it (including the quote, if possible).