Originating 1970s from Tilbury Docks Essex, from the old timber ships (the timber was called "green" cargo and if you dropped a pack of it, you would have an aching back after you picked it up! - Knocking over of cargo/accident resulting in the picking up of somthing heavy.
Forklift driver knocks over a stack of pallets - "Bills just had a green acher!"
Levi Ackerman is a hot captain who is the greatest titan killer humanity has ever faced. This captain is kind of short for his age but who gives a shit Levi does not. If you say your mind to Levi bad idea buddy cause you got a beat down coming your way from Levi. But god damn he is hot. Also he takes 2-3 hour bedtimes. And guess what he sleeps in a chair! But we all do it time to time.