Learner's definition of DRIVER
1 a : a person who drives a car, truck, etc.
b : a person whose job is to drive a vehicle (such as a taxi, truck, or bus)
Who was the driver at the time of the accident?
He's a good/careful/fast/bad driver.
The front door on the driver's side [=the side of the car where the driver sits] is scratched.
We told the taxi driver to take us to the library.
He likes to sit at the front of the bus, near the driver.
an ambulance/truck driver
2 technical : a piece of computer software that controls a device (such as a mouse or printer) that is attached to the computer 3 golf : a club that is used for hitting long shots off a tee
in the driver's seat
: in a position in which you are able to control what happens