On the Aridor Slave Rescue game, to un-BG a character is the opposite of to BG a character. It means, getting rid of the bodyguards assigned to a character, so they can be captured by ordinary means. It is used to refer both to situations where a player deliberately gets rid of the bodyguards on their own character (by losing a contest for instance), and where a player rumbles or biobombs another in order to get rid of BGs.

When you eat dirt for the first time and leave your family to build a shack in the woods