ploonet

Etymology
. Coined in 2019 by the research team of Mario Sucerquia,  Jaime A Alvarado-Montes,  Jorge I Zuluaga,  Nicolás Cuello,  Cristian Giuppone (see quotations below).

Noun

 * 1)  A theoretical planetary body that formed as a moon orbiting a planet, but which has become tidally detached, so that it enters orbit about its star, separated from its parent planet.

Translations

 * Japanese: プルーネット
 * Korean: 플루넷