Meaning of radioiodine

ra•di•o•i•o•dine

Pronunciation: (rā"dē-ō-ī'u-dīn", -din, -dēn"), [key]
— n. Chem.
  1. any of nine radioisotopes of iodine, esp. iodine 131 and iodine 125, used as radioactive tracers in research and clinical diagnosis and treatment.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.