isomer isomenthone • Isomera · · · Info · Definitions · Characters · · isomer · · Text Latin · · Script 6 · · Length Definitions · · · (noun) a compound that exists in forms having different arrangements of atoms but the same molecular weight. · · Noun Definition 1 Characters · · e latin small letter e U+0065 i latin small letter i U+0069 m latin small letter m U+006D o latin small letter o U+006F r latin small letter r U+0072 s latin small letter s U+0073