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