mass noun mass murderer • mass number · · · Info · Definitions · Characters · · mass noun · · Text Common · · Latin · · Scripts 9 · · Length 2 · · Syllables Definitions · · · (noun) a noun that does not form plurals. Synonyms: mass noun. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 m latin small letter m U+006D n latin small letter n U+006E o latin small letter o U+006F s latin small letter s U+0073 u latin small letter u U+0075