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