A dd and I, both linguistically minded, often used to amuse ourselves by looking up words in a very fat dictionary that gave origins/first noted usage, etc. I still do now and then.
One I particularly remember was ‘acre’. This came about because a Swedish friend’s son who’d got a job in London was coming to stay with us. Having never met him I had to wait at Heathrow with his name on a placard - it was Aker, with a little circle thing over the A.
I later asked him whether it meant anything in Swedish - yes, it meant ‘field’. So I thought, aha, I wonder if it’s related to ‘acre’? Sure enough, it was - the Anglo Saxon version meant the amount of land that could be ploughed by 2 oxen in a day.
Not only that, but there are very similar words with the same meaning in Dutch and German, not to mention Latin and Greek, all going back to an Indo-European root shared by Sanskrit.
Another one I like is riff-raff, which in Anglo Saxon apparently meant ‘sweepings of rags’!
I hope I’m not the only one who finds such things fascinating!
To think that London, or anywhere else for that matter, does not belong to any one demographic