This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. The condition of being pernicious; destructiveness

n. The character of being pernicious, very injurious, mischievous, or destructive; hurtfulness.

n. grave harmfulness or deadliness

""perniciousness" with which they were reproached was nothing else but their opposition to the established polytheism; and this view of the matter was just such an one as might be expected to occur to a mind which held the sect in too much contempt to concern itself about the grounds and reasons of their conduct."

morbidness    morbidity    unwholesomeness