onerousness onerously • onery · · · Info · Definitions · Synonyms · Characters · · onerousness · · Text Latin · · Script 11 · · Length Definitions · · · (noun) unwelcome burdensome difficulty. Synonyms: burdensomeness, heaviness, oppressiveness. · · Noun Definition 1 Synonyms · · · burdensomeness · · Synonym 1 heaviness · · Synonym 2 oppressiveness · · Synonym 3 Characters · · e latin small letter e U+0065 n latin small letter n U+006E o latin small letter o U+006F r latin small letter r U+0072 s latin small letter s U+0073 u latin small letter u U+0075