An acronym for "good luck I guess".
Mainly used when people choose to defy your advice on a particular matter.
Customer: Hi, I need help with this.
Specialist: Sure, you need to do XY and Z before you go ahead with it.
Customer: Nah, I think I'll still go ahead without doing XY and Z.
Specialist: Cool. GLIG.
A version of a person, who is fat, but as a jokingly way to call them a pig. (can be insulting.) This is a term used by some people around New jersey, New york, and Delaware.