indicator - noun

  • a number or ratio (a value on a scale of measurement) derived from a series of observed facts; can reveal relative changes as a function of time
  • a signal for attracting attention
  • a device for showing the operating condition of some system
  • (chemistry) a substance that changes color to indicate the presence of some ion or substance; can be used to indicate the completion of a chemical reaction or (in medicine) to test for a particular reaction
  • indicator - thesaurus

    index   indicant