It’s a little embarrassing, but I don’t know where my nick comes from. I use to believe that it was my invention, but in a Yahoo and Google search I found it in a language I can’t identify:
It’s definitely not Esperanto. It seems to be Letzebuergisch (a German dialect spoken in Luxemburg, one of Luxemburg’s three official languages, the other ones being French and German). What it means I don’t know (sounds suspiciously like the German word for “great”), but Letzebuergisch is mentioned in all of your three sites, so I’m confident it is.
I had a history teacher (WWII Vet) that used to always say “Quit your grousing” meaning complaining or bitching. If you seem to be predisposed to voicing objections, this may be your answer. Your other option is to ask one of the people that first called you that and ask “why”? Just an opinion.
Sorry, dnooman, please read the early posts. I once “invented” the word, for a character in a game, but I didn’t know the word existed already. The posts from Schnitte and Floater go into the right direction. Now the question is if it really means “great” in Letzebuergisch or what.
I’d always thought I’d invented my nick, too, Grousser. When I googled my name, it turns out the first several hits are for something called the Orange Skinner Bible, from the Elizabethian Era, IIRC. There really isn’t anything new under the sun, dammit.
If it’s used like that, I’d wager a guess that it is a german dialect and these quotes stand for ‘grosser Musik’ or ‘grosser Erwartung’. Which translate roughly to ‘large/great Musik’ or ‘great expectation’. German nouns are spelled with a starting capital. Schnitte or any other German doper might be able to improve on this guess.