What is the root meaning of guay?

There is no word "guay" in English or any major language. It's likely you're thinking of a different word, perhaps one with a similar spelling or sound.

To help me understand your query, could you please provide more context? For example:

* Where did you encounter this word? (In a book, a conversation, a song, etc.)

* What was the word's context? (What was being discussed or described?)

* What language do you think it might be from?

With more information, I can help you understand the meaning of the word you're looking for.