coolant system vs cooling

coolant system and cooling both are nouns.

Word	Noun	Adjective	Verb	Adverb
coolant system	Yes	No	No	No
cooling	Yes	No	No	No

As nouns, cooling is a hypernym of coolant system; that is, cooling is a word with a broader meaning than coolant system:

coolant system: a cooling system that uses a fluid to transfer heat from one place to another
cooling: a mechanism for keeping something cool

Other hypernyms of coolant system include cooling system.

coolant system (noun)	cooling (noun)
a cooling system that uses a fluid to transfer heat from one place to another	a mechanism for keeping something cool
	the process of becoming cooler; a falling temperature