[¦thrē ¦fīv dī¦ī·ə‚dō‚sal·ə′sil·ik ′as·əd] (organic chemistry) C7H4I2O3 Crystals with a sweetish, bitter taste and a melting point of 235-236°C; soluble in most organic solvents; used as a source of iodine in foods and a growth promoter in poultry, hog, and cattle feeds.