iridium iridite • iridization · · · Info · Definitions · Synonyms · Characters · · iridium · · Text Latin · · Script 7 · · Length Definitions · · · (noun) a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium. Synonyms: Ir, atomic number 77. · · Noun Definition 1 Synonyms · · · ir · · Synonym 1 atomic number 77 · · Synonym 2 Characters · · d latin small letter d U+0064 i latin small letter i U+0069 m latin small letter m U+006D r latin small letter r U+0072 u latin small letter u U+0075