layover vs pit stop

layover and pit stop both are nouns.

Word	Noun	Adjective	Verb	Adverb
layover	Yes	No	No	No
pit stop	Yes	No	No	No

As nouns, pit stop is a hyponym of layover; that is, pit stop is a word with a more specific, narrower meaning than layover:

layover: a brief stay in the course of a journey
pit stop: a brief stop at a pit during an automobile race to take on fuel or service the car

Other hyponyms of layover include night-stop, stand.

layover (noun)	pit stop (noun)
a brief stay in the course of a journey	a brief stop at a pit during an automobile race to take on fuel or service the car
	a stop during an automobile trip for rest and refreshment