What is an idle suffix?

There is no commonly recognized term called "idle suffix". It's likely that you've encountered a different term or concept.

Could you please provide more context? For example:

* Where did you see or hear this term? (e.g., in a book, a website, a conversation)

* What was the topic being discussed? (e.g., programming, linguistics, etc.)

* What do you think it means?

With more information, I can help you understand what you're looking for.