planemo

noun

a) a planetary mass object; an astronomical object with enough mass to be considered a candidate planet, and not too much mass to become a brown dwarf, were it to meet the other criteria required for being a planet; a celestial object that has enough self-gravitation to overcome its physical and chemical composition to become spheroidal due to hydrostatic equilibrium, but not enough mass to overcome nuclear repulsion and start fusing deuterium.

b) a heavenly body that is round due to self-gravity and not massive enough to initiate any kind of core fusion