Real Life is everything outside of WoW, like real eating and sleeping, jobs, school, family, gatherings, etc. You know, All those things you read about on MSN Today. It is still unknown if such a thing truly exists. It is rumored to be a conspiracy put out by Blizzard to control the minds of their players. There is no real proof saying that 'Real Life' actually exists.
Usually abbreviated to RL in chat.