The term planetary mass object (or PMO) is sometimes used when the object's mass does (or might) fall in the range of a planet or dwarf planet, even if it isn't classified to be or confirmed to be a planet. So planets and dwarf planets qualify. The term may be used if for some reason the object is unlike typical and/or known planets: to concoct an example, with an orbit so elliptic that it is comet-like. It also might be used for free-floating objects, i.e., not in a planetary system.
The term sub-brown dwarf is used for such an object that formed like a star but only achieved the mass of a planet, i.e., less mass than a brown dwarf.