driver
noun [ C ]
uk/ˈdraɪvər/ us TRANSPORT
someone who drives a vehicle:
You may get nothing in an accident if the other driver is uninsured.
a bus/lorry/truck driver
IT
a computer program that makes it possible for a computer to use other pieces of equipment such as a printer:
a printer driver
something that makes other things progress, develop, or grow stronger:
Momentum-based investing is the most prominent of the new market drivers.
an important/a key/a major driver of sth Service sector output is up 1.2% in the latest quarter making it, by far, the major driver of growth once more.
be in the driver's seat US
→ be in the driving seat