iodine

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
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    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
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    type of:
    antiseptic
    a substance that destroys micro-organisms that carry disease without harming body tissues
    tincture
    (pharmacology) a medicine consisting of an extract in an alcohol solution
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