A "planet" that does not orbit a star, or in other words, a "floating" planet. Artistic reproduction.
Paris Observatory / UFE
Planets more massive than 13 Jupiters
There's no reason why some planets cannot be less massive than 13 times that of Jupiter at the beginning of their formation, and then grow up to attain a mass greater than this limit.
There is nothing to stop some stars from forming through the collapse of dust and gas clouds without reaching the limit mass of 13 Jupiters. These stars are planets following the first definition, but they do not orbit a star. They are called "floating" planets.