iodine

/ˌaɪəˈdaɪn/

/ˈaɪədin/

Other forms: iodines

Definitions of iodine

1. noun

   a nonmetallic element belonging to the halogens; used especially in medicine and photography and in dyes; occurs naturally only in combination in small quantities (as in sea water or rocks)
   synonyms: I, atomic number 53, iodin

   types:

   iodine-131

   heavy radioactive isotope of iodine with a half-life of 8 days; used in a sodium salt to diagnose thyroid disease and to treat goiter

   iodine-125

   light radioactive isotope of iodine with a half-life of 60 days; used as a tracer in thyroid studies and as a treatment for hyperthyroidism

   type of:

   chemical element, element

   any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter

   halogen

   any of five related nonmetallic elements (fluorine or chlorine or bromine or iodine or astatine) that are all monovalent and readily form negative ions
2. noun

   a tincture consisting of a solution of iodine in ethyl alcohol; applied topically to wounds as an antiseptic
   synonyms: tincture of iodine

   type of:

   antiseptic

   a substance that destroys microorganisms that carry disease without harming body tissues

   tincture

   (pharmacology) a medicine consisting of an extract in an alcohol solution