Bog in itself, the swampy meaning, is from scots. It's related to the english word "bow", because the ground is "bendy" in a swamp, doonchanoo?
However, the bog I mentioned is a shortening for boghouse, which seems to be an english invention, using an argot verb "to bog = to defecate".
Situation normal, all bogged up!

I had to look up argot too... it's a secret vocabulary peculiar to a certain group... so, it's some group's jargon. Argot sounds cooler though.
Argot argot argot.