What's the plural form of ringmail? Here's the word you're looking for.
Answer
The noun ringmail can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be ringmail.
However, in more specific contexts, the plural form can also be ringmails e.g. in reference to various types of ringmails
or a collection of ringmails.
My jeans and T-shirt were quickly replaced by a thick quilted coat called a gambeson and it took three experienced re-enactors to drape me in a ringmail shirt.