chemical plant vs mill

chemical plant and mill both are nouns.

Word	Noun	Adjective	Verb	Adverb
chemical plant	Yes	No	No	No
mill	Yes	No	Yes	No

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

chemical plant: an industrial plant where chemicals are produced
mill: a plant consisting of one or more buildings with facilities for manufacturing

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

chemical plant (noun)	mill (noun)
an industrial plant where chemicals are produced	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

chemical plant (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