HI

Hydriodic Hy`dri*od"ic, a. [Hydr- + iodic: cf. F. hydriodique.] (Chem.) Pertaining to, or derived from, hydrogen and iodine; -- said of an acid ({HI}) produced by the combination of these elements. [1913 Webster]

{Hydriodic acid} (Chem.), a pungent, colorless gas, {HI}, usually prepared as a solution in water. It is strong reducing agent. Called also {hydrogen iodide}. [1913 Webster]