car factory vs mill

car factory and mill both are nouns.

Word	Noun	Adjective	Verb	Adverb
car factory	Yes	No	No	No
mill	Yes	No	Yes	No

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

car factory: a factory where automobiles are manufactured
mill: a plant consisting of one or more buildings with facilities for manufacturing

Other hypernyms of car factory include factory, manufactory, manufacturing plant.

car factory (noun)	mill (noun)
a factory where automobiles are manufactured	the act of grinding to a powder or dust
	machinery that processes materials by grinding or crushing
	a plant consisting of one or more buildings with facilities for manufacturing

car factory (verb)	mill (verb)
	grind with a mill
	produce a ridge around the edge of
	roll out (metal) with a rolling machine
	move about in a confused manner