atomic number 55 atomic number 54 • atomic number 56 · · · Info · Definitions · Synonyms · Characters · · atomic number 55 · · Text Common · · Latin · · Scripts 16 · · Length 8 · · Syllables Definitions · · · (noun) a soft silver-white ductile metallic element (liquid at normal temperatures); the most electropositive and alkaline metal. Synonyms: cesium, caesium, Cs, atomic number 55. · · Noun Definition 1 Synonyms · · · cesium · · Synonym 1 caesium · · Synonym 2 cs · · Synonym 3 Characters · · space U+0020 5 digit five U+0035 a latin small letter a U+0061 b latin small letter b U+0062 c latin small letter c U+0063 e latin small letter e U+0065 i latin small letter i U+0069 m latin small letter m U+006D n latin small letter n U+006E o latin small letter o U+006F r latin small letter r U+0072 t latin small letter t U+0074 u latin small letter u U+0075