X post in weeds
Is this a weed or a perennial?
I'm pretty sure it's a horehound of some kind which yes, most people would consider a weed. Does it smell vaguely minty?
Might be catnip/catmint.
Yeah that's a good call, probably more likely in a garden. Though many Lamiaceae look sort of like this. Could even be a plectranthus seedling but obviously that would not be so far along in zn 6.
At any rate, a lot of people consider catnips weeds, unless desired! Mints, catnips, even Monardas, they all spread like crazy if they are happy.
I don't think it's catmint or horehound since it doesn't really have a minty scent. It smells like a green leafy vegetable. Also, the leaves are very large. I know it's hard to tell scale in that photo, but the bottom leaves are almost 10" long.
Check the stem. If it's square, it belongs somewhere in the mint family.