A "Kebert" is a funny one that often times pulls shanagans without thought and often times doesn't realize the horrible outcome that could occur. Being a "kebert" isn't always a bad thing, often times the "Kebert" can be hilarious and often times be one of enjoyment.
"Don't be such a kebert and put down my phone"
"Kebert, why are you here? Isn't this your 4th DUI"