There are two "planet" definitions, depending on if the object in question is in the solar system or outside. The terminology for the later is not as well settled. You might see "free floating planet" or "rogue planet" or the more general term "planetary-mass object" (or PMO or planemo). (The actual paper uses 'free floating planet' and 'planetary-mass object'.)
In any case, if the official position is that a "dwarf planet" is not a planet then it's not hard to see that a "free floating planet" need not be a "planet."
In any case, if the official position is that a "dwarf planet" is not a planet then it's not hard to see that a "free floating planet" need not be a "planet."