evilness has 1 distinct synonym spread across 1 of its 1 sense. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is goodness.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
the quality of being morally wrong in principle or practice
“attempts to explain the origin of evil in the world”
Synonyms, antonyms and the broader and narrower relations for evilness come from Princeton University’s WordNet. Full sources and licences.