Im not really into the English language, but i'm curious as to why certain words come into the main stream. I work in IT in London, and I'm, used to males greeting each other as "mate", "John" "Pal" etc, but in recent years I've noticed the word "fellow" being used a lot, the first time I heard it used commonly was in 2003, I think it's a south London thang, anyone have any idea's?
I am thousands of miles away, so I can't say I have heard it, but in slang there's often what's called overlexicalisation, which means that there are a ridiculous number of terms for the same thing, like the hundreds of ways of saying drunk. If, as you say, it's predominantly from Soth London, then it's very likely that someindividual started using it and it took off. In London slang, there are many examples of 'posh' words being adopted, like 'chronic', so it could be from 'my good fellow' or it could be an imitation of a view of a particular type of South Asian English speaker that sounded good in south London. Usages can be infectious.