driver vs coachman

driver and coachman both are nouns.

Word	Noun	Adjective	Verb	Adverb
driver	Yes	No	No	No
coachman	Yes	No	No	No

As nouns, coachman is a hyponym of driver; that is, coachman is a word with a more specific, narrower meaning than driver:

Other hyponyms of driver include charioteer, lasher, mahout, teamster, waggoner, wagoner.

driver (noun)	coachman (noun)
a golf club (a wood) with a near vertical face that is used for hitting long shots from the tee	a man who drives a coach (or carriage)
(computer science) a program that determines how a computer will communicate with a peripheral device
the operator of a motor vehicle
a golfer who hits the golf ball with a driver
someone who drives animals that pull a vehicle