A substance in vapor form that is in the presence of some of its own liquid is a _________________ vapor.

The correct choice is saturated vapor, which refers to a condition where vapor exists in equilibrium with its own liquid at a given temperature and pressure. When a substance reaches this point, it means that the vapor cannot hold any more liquid; adding more liquid would result in some of it condensing back into the liquid phase. This equilibrium indicates that the vapor consists of molecules that have sufficient energy to remain in the vapor phase while also being sufficiently close to the liquid phase, hence maintaining a balance.

Saturated vapor is distinct from dry vapor, which contains no liquid molecules and does not have any liquid phase present. Unlike superheated vapor, which is vapor heated beyond its boiling point without increasing pressure, saturated vapor remains at the boiling point relevant to its pressure. Pressurized vapor could refer to vapor in a confined space at high pressure, but it does not specifically convey the relationship with the liquid phase like saturated vapor does. Thus, the term saturated most accurately describes the described scenario where vapor coexists with its liquid.