car park vs lot

car park and lot both are nouns.

Word	Noun	Adjective	Verb	Adverb
car park	Yes	No	No	No
lot	Yes	No	Yes	No

As nouns, lot is a hypernym of car park; that is, lot is a word with a broader meaning than car park:

car park (noun)	lot (noun)
a lot where cars are parked	anything (straws or pebbles etc.) taken or chosen at random
	an unofficial association of people or groups
	any collection in its entirety
	a parcel of land having fixed boundaries
	(often followed by `of') a large number or amount or extent
	your overall circumstances or condition in life (including everything that happens to you)

car park (verb)	lot (verb)
	administer or bestow, as in small portions
	divide into lots, as of land, for example