I always thought of 'resinous' almost as a mouthfeel component. Its not the type of hop flavors, but the way they coat and stick to my palate.
That would actually make sense to me. But it's usually used in reference to flavor.
I understand "piney" or "pine resin," but resin itself doesn't make much sense to me.
"Dank" makes me think of a feeling or atmosphere, not flavor.
So, what I get from this thread (besides that y'all are a bunch of stoners), is that "resin" and "dank" as flavor descriptors are ambiguous and therefore useless. If we can't think of something known and familiar to use as a reference, why make s*** up?