I’ve been watching The Expanse on and off throughout the seasons, and I recently binge watched season 4.  One word that constantly comes up when referring to certain individuals is “belter”.

The last few episodes of Season 4 held my attention enough for me to want to look it up.  So, for casual fans of the show who have dropped in and out, like me, it means:

Belter is a term used to refer to persons born in the Asteroid Belt or the Moons of the outer planets. In a pejorative meaning, they are also called Skinnies, because of their altered physics due to growing up and living in a low gravity environment.

Source: https://expanse.fandom.com/wiki/Belter