What's the plural form of irradiancy? Here's the word you're looking for.
Answer
The noun irradiancy can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be irradiancy.
However, in more specific contexts, the plural form can also be irradiancies e.g. in reference to various types of irradiancies
or a collection of irradiancies.
Examples
The principal and most gemmary affection is its translucency, and as for irradiancy or sparkling, which is found in many gems, it is not discoverable in this.
