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