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