ruthenium ruthenious • ruthenous · · · Info · Definitions · Synonyms · Characters · · ruthenium · · Text Latin · · Script 9 · · Length Definitions · · · (noun) a rare polyvalent metallic element of the platinum group; it is found associated with platinum. Synonyms: Ru, atomic number 44. · · Noun Definition 1 Synonyms · · · ru · · Synonym 1 atomic number 44 · · Synonym 2 Characters · · e latin small letter e U+0065 h latin small letter h U+0068 i latin small letter i U+0069 m latin small letter m U+006D n latin small letter n U+006E r latin small letter r U+0072 t latin small letter t U+0074 u latin small letter u U+0075