My first thoughts were (1) poison ivy, (2) blackberry, and (3) really big mint...but I really have no idea. Are the stalks hairy or have briars on them? It looks like mint in the background, but I've never seen mint get this big. Any smell to the plant if you crush the leaves? (but don't handle them unless you know it isn't poison ivy!).
not mint....but I see the mint beside it
reminds me of lambsquarter but that's not what it is
It is some kind of weed.My neighbor knows the name for it so i am asking her, will get back with ya!
It is a weed. I remember pulling tons of them in the potatoe patch when I was a kid
Night shade is what it looks like to me. A weed that you need to eliminate if that is what it is. I would take some to your county extension agent ASAP and find out!