If you ever find yourself within
chatrooms in the
transvestite,
transsexual or
transgender area of the
internet then the
abbreviation 'GG' takes on a different meaning, that being
Genetic Girl. Or
Genuine Girl, if you prefer - both mean the same thing. This usually means that the person using it was either
born female or has
merely tacked the letters 'GG' to the end of their name to pretend.
In gaming terms, as a result of my extended liason with Yahoo! Pool, 'GG' seems to have lost its meaning due to overuse*. Instead of meaning, "Hey, that was a damn good game and I thoroughly enjoyed it. Thanks", it's become some standard quick line to stick at the end of any online multiplayer game.
The T*Girl Team Fortress League regularly collapse into fits of confusion over this abbreviation's unfortunate double meaning.
* see also: lol. speaking personally, i can't seem to help reading that one with a deadpan tone of voice.