Requesting advice- A Philosophy Idea

I’m not sure about this, but presenting it anyway for scrutiny.

I was thinking that it doesn’t matter if a concept is undefined, or even cannot be defined, if hypothetically speaking said concept can exist without any ambiguity within it then it is still a tenable concept. The implications, if this is true, would be that it would knock down Quine’s argument against the analytic-synthetic distinction.

Your thoughts, Lesswrong?