Dayz has been a handle used online since 1997. It originated from a AOL screename which "Ina" or "Dayz" could have been chosen. Dayz was chosen and has been known in online hacking communities ever since.
When you run with a group of people on DayZ for a fat minute, then switch up to play with someone new for a few days while appearing offline, only to have your friends join the party on alt accounts to find you and said person together.
Squad: I can't believe you, I thought you were rollin with us?
Victim: I am, I'm just---
Squad: I don't wanna hear it. I can't believe you're DayZ Cheating on us.
A sunburn or suntan focused on the left arm. It is caused by the left side of the body being the only half that gets exposed to sunlight while driving. Presumably, it would be located on the right side of the body in countries where they drive on the left side of the road.
British slang for a scientist or technical expert, esp . when the speaker is not certain of the expert’s specific field of study. Not necessarily derogatory, but typically used by persons without a technical background. In the US, the equivalent would be “egghead”, “squint”, or “geek.”
Origin of the word is unknown. Started sometime in World War 2. Given the typical evolution of British slang, could easily have started because what these experts did was confusing or “baffling” to the common person.