If the object is above the deuterium-burning limit then it is a brown dwarf. If it's below, then as it is orbiting a star, it is a planet according to the Position Statement on the Definition of a "Planet" of the IAU's Working Group on Extrasolar Planets.

"Luhman and others advocate that an object is a planet only if it formed from the disk of gas and dust that commonly encircles a newborn star." But that criteria is not in the IAU position statement, which tends to suggest that is disputed!. (A lot of people think you should base a definition on what an object is, not how it came to be.)