atomic weight atomic weapon • atomiferous · · · Info · Definitions · Synonyms · Characters · · atomic weight · · Text Common · · Latin · · Scripts 13 · · Length 5 · · Syllables Definitions · · · (noun) (chemistry) the mass of an atom of a chemical element expressed in atomic mass units. Synonyms: atomic mass, atomic weight, relative atomic mass. · · Noun Definition 1 Synonyms · · · atomic mass · · Synonym 1 relative atomic mass · · Synonym 2 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 e latin small letter e U+0065 g latin small letter g U+0067 h latin small letter h U+0068 i latin small letter i U+0069 m latin small letter m U+006D o latin small letter o U+006F t latin small letter t U+0074 w latin small letter w U+0077