What's the plural form of damnableness? Here's the word you're looking for.
Answer
The noun damnableness can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be damnableness.
However, in more specific contexts, the plural form can also be damnablenesses e.g. in reference to various types of damnablenesses
or a collection of damnablenesses.