Pronunciation: (trī"ī-ō"dō-thī'ru-nēn", -ī-od"ō-), [key]
1. Biochem.a thyroid hormone, C15H12I3NO4, similar to thyroxine but several times more potent.
2. Pharm.a preparation of this hormone, used in treating hypothyroidism. Abbr.: T3
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.