origin of "muggle"

[Jonathon Green]

>
> I've seen American fan sites that have insisted that 'muggle' is British
> slang for 'loser'.  Just found a case of this at:
> <http://savage.authorslawyer.com/journals/j_9c.shtml>, which says:
> "Rowling's books use British slang extensively, and "muggle" has meant
> "complete loser" since the 19th century."
> [...]
> But I've never heard any such thing in the UK

Me neither. Muggle is not now, definitely, and never has been, to my
knowledge,  a term for 'loser' in UK slang. One must assume that those who
make this claim, for whatever reason, are confusing it with 'mug', which
has meant a dupe or fool, usually from a criminal's viewpoint, from at
least 1821 (when it appears in Jon Bee's _Real Life in London_). The first
appearance of 'muggle' or more usually 'muggles' in the slang lexicon is,
as Lynne Murphy suggests, in the context of marijuana (a Louis Armstrong
title of 1928; it was slightly preceded by 'mugglehead', a marijuana
smoker, listed in 1926), and as such was never in any case a very
widespread UK term. Rowling can be presumed to be honest when she claims
never to have encountered it.

Jonathon Green