1. Typically used in the context of a fight, when one's shit is rocked so badly that their body bends over at the waist, hence "folding"
2. as an extension of the original definition, "folded" is used as a replacement for "destroyed" or "ended"
1.
guy 1: "did you see the fight yesterday in the bathroom?
guy 2: "yeah bro, travis got folded"
2.
guy 1:"who do you think is the strongest hero?"
guy 2: "the flash! he could EASILY fold the whole justice league