Living on the edge means living a dangerous and/or unusual everyday life. People who live on the edge are very frequently exposed to phisical, psycological, economical,
lawful or other kinds of
dangers.
Examples for people who live on the edge:
Extreme-sportsmen, gamblers,
policemen, thiefs, human-rights-activists, rappers, etc.
-My friend John is
living on the edge.
-Oh yeah? He is a
gambler or something?
-No, he
cleans windows of high office buildings.