From the
root word "Yokel". It is generaly used as a derogatory term for a bad driver, however it can also be used to describe someone as
inferior mentally. It implies a certain level of redneck
culture and inbreeding in the driver or person it is being yelled at.
When you come around a
corner to find someone stopped in the middle of the highway, "What is this Yoker doing?"
When someone tries to pass you when you
stop for a flagger in a construction zone and almost runs head first into oncoming traffic, "You freakin Yoker!"
When someone tries to impress
people by doing something he has very littke skill or experience in, "What a yoker!"