What does iodide mean?
An iodide is a chemical form of iodine in which iodine has gained an electron and carries a negative charge. The term can refer to the iodide ion itself, written I⁻, or to a compound formed when iodide combines with another element, such as potassium iodide or sodium iodide. In nutrition and medicine, iodide is the form of iodine used by the thyroid gland to produce thyroid hormones, which help regulate metabolism and other important bodily functions. Iodide therefore differs from iodine, which is the chemical element and the broader term for all of its forms. The distinction is especially important in technical writing, where oxidation state and electrical charge are significant. Although iodide is essential in small dietary amounts, excessive exposure can be harmful, particularly in people with thyroid disease.
nounA chemical compound or ion containing iodine in the negatively charged oxidation state −1, typically formed with a metal or hydrogen. In medicine, iodide refers to the iodide ion, the form in which iodine is present in dietary iodide and thyroid-related preparations.
- A chemical ion or compound containing iodine with a charge of −1 or an iodine atom in the −1 oxidation state.
- The iodide ion in nutritional and medical contexts, especially in relation to iodine supplementation and thyroid function.
"Potassium iodide is used to provide iodine in the diet and has also been used during emergency situations involving radioactive contamination."
"The iodide ion combines with sodium to form sodium iodide."
"The doctor recommended an iodide-containing supplement for the patient's iodine deficiency."
The plural is used for different iodide compounds or for multiple instances or measurements of iodide.
"Several iodides are soluble in water."
Your thyroid relies on iodide to help make the hormones that regulate metabolism.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of iodide
The word derives from iodine, whose name comes from Greek iōdē, meaning “violet,” because of the colour of iodine vapour. The suffix -ide was added to indicate a negatively charged ion or a compound containing that ion. Related chemical terms such as iodate and iodic share the same Greek-derived root.
Related word forms
How iodide is actually used
The term is primarily technical and is used more in chemistry, medicine, and nutrition than in everyday speech. When referring specifically to the negatively charged ion, “iodide” is commonly used without an article in technical contexts.
Easily confused with iodide
Iodine is the chemical element, whereas iodide is the negatively charged ion or a compound containing that ion.