tennis coach vs coach

tennis coach and coach both are nouns.

Word	Noun	Adjective	Verb	Adverb
tennis coach	Yes	No	No	No
coach	Yes	No	Yes	No

As nouns, coach is a hypernym of tennis coach; that is, coach is a word with a broader meaning than tennis coach:

Other hypernyms of tennis coach include handler, manager.

tennis coach (noun)	coach (noun)
a coach of tennis players	a carriage pulled by four horses with one driver
	a railcar where passengers ride
	a vehicle carrying many passengers; used for public transport
	a person who gives private instruction (as in singing, acting, etc.)
	(sports) someone in charge of training an athlete or a team

tennis coach (verb)	coach (verb)
	teach and supervise (someone); act as a trainer or coach (to), as in sports
	drive or operate a coach or carriage