It's creates from the two words Coronavirus + Quarantine = Corontine
You use it for saying you are in quarantine, because you are having Coronavirus and you must be in quarantine.
Coronie is a term that is typically used to describe a fellow worker of the same yard/report location that drives a bus. They are usually miserable because they get paid less compared to other transit agencies in the vicinity. When they are off duty and see any bus, they get very excited and go out of their way to tell their buddies who are in the car about the presence of a coronie.
Whilst on the 70th lap of the Line 22 Hotel for the homeless, the driver spots a fellow worker driving in the opposite direction... "there goes my coronie".
An infected individual with COVID 19 who willingly and intentionally spreads the virus to the community by contaminating public facilities such as, shopping carts, elevators, ATMs, door handles and etc.
Dude, Look at that man! He's probably trying to coronize that shopping cart!