ez is used when someone, preferably a gamer, wins a game or gets a kill.
In games with a chat, the person usually types "ez" which means "easy".
((a shorter way of typing "easy")).
But, some no-lifers use the word "ez" when they have nothing to say.
EZ is Express Zone in an elevator. That is when the real elevator is in the shaft where there are no "Shaft doors". Shaft doors are the front elevator doors, which you see when you come to an elevator bank, outside of the real elevator(s). EZ is shown on the Elevator Indicator.
The elevator indicator shows EZ!
There are no shaft doors, so the elevator indicator shows EZ.