Well, this term "higher-kinded" is well known in FP-community. I don't like introducing confusion, but higher-kinded graphs have something in common with higher-kinded types. If you judge I'm trying to seem smart without having a good grasp in type theory, please let me know in the comment section below.
Higher-kinded graphs are graphs that use inferior graphs as binary codes on the binary level. Here I'm writing once again about multimodal graphs with a selected root vertex and so on. Of course, the constituent graphs are reduced to just one number by a hash function. And certainly, the order of entries plays a role.
What struck me this morning, is that those superior (or more abstract) graphs can contain paths, that run within the inferior graphs. It's a sort of glue that binds together several more concrete graphs. Concrete graphs may be larger in size, actually.