osmium osmiridium • osmodysphoria · · · Info · Definitions · Synonyms · Characters · · osmium · · Text Latin · · Script 6 · · Length Definitions · · · (noun) a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known. Synonyms: Os, atomic number 76. · · Noun Definition 1 Synonyms · · · os · · Synonym 1 atomic number 76 · · Synonym 2 Characters · · i latin small letter i U+0069 m latin small letter m U+006D o latin small letter o U+006F s latin small letter s U+0073 u latin small letter u U+0075