The Collaborative International Dictionary
Iridious
Iridious \I*rid"i*ous\ ([-i]*r[i^]d"[i^]*[u^]s), a. (Chem.) Of or pertaining to iridium; -- applied specifically to compounds in which iridium has a low valence.
Wiktionary
iridious
a. (context chemistry English) containing trivalent iridium