paper mill vs mill

paper mill and mill both are nouns.

Word	Noun	Adjective	Verb	Adverb
paper mill	Yes	No	No	No
mill	Yes	No	Yes	No

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

paper mill: a mill where paper is manufactured
mill: a plant consisting of one or more buildings with facilities for manufacturing

Other hypernyms of paper mill include factory, manufactory, manufacturing plant.

paper mill (noun)	mill (noun)
a mill where paper is 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

paper mill (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