There is a similar phrase in French, à bas, that is translated down with and I believe is used to mean the same as discussed by other answers - do away with. 

I am not sure when down with was first used in the U.S., but MW claims the first documented usage of à bas in French is 1897.

What does "down with homework" mean?
I have a sweet ravine balcony, that I've lit up, and partially fenced off. It's not connected to anywhere that mobs could spawn yet, come night zombies are at my door creepers are lounging around and spiders are crawling around! I didn't invite them!






Is there any reason for these mobs to spawn here when it's well lit?
