What's the plural form of mongrelism? Here's the word you're looking for.
Answer
The noun mongrelism can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be mongrelism.
However, in more specific contexts, the plural form can also be mongrelisms e.g. in reference to various types of mongrelisms
or a collection of mongrelisms.
Examples
It has all the hybrid vigour of mongrelism and once they learn to speak it properly, world cultural domination will be complete.
Apparently the correct definition of his mongrelism is that he is a retriever and Tibetan spaniel cross.