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