[ rey-dee-oh-ahy-uh-dahyn, -din, -deen ]
/ ˌreɪ di oʊˈaɪ əˌdaɪn, -dɪn, -ˌdin /

noun Chemistry.

any of nine radioisotopes of iodine, especially iodine 131 and iodine 125, used as radioactive tracers in research and clinical diagnosis and treatment.

Origin of radioiodine

First recorded in 1935–40; radio- + iodine Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Medicine definitions for radioiodine


[ rā′dē-ō-īə-dīn′ ]


A radioactive isotope of iodine widely used as a tracer.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.