But true Moka laughed at him for thinking that turning into a vampire would be as simple as her injecting blood into him. So you're right when you call him more of a mixture I guess. Ghoul doesn't have to mean some sort of zombie thing though. I mean, it makes sense that a human vampire hybrid would have a specific name, since Tsukine has almost as much power as her at this point but none of the weaknesses associated with being a vampire.
And it looks like vampires aren't the only ones who can transform humans with blood injections if Aizen is any indication.