The quality or state of being criminal or wicked.
From criminous + -ness (suffix forming abstract nouns expressing state or quality), following the standard pattern for creating noun forms from adjectives.
The -ness suffix is so powerful in English that you can add it to almost any adjective to create a noun—even forgotten words like criminousness suddenly have a 'thingness.'
Complete word intelligence in one call. Free tier — 50 lookups/day.