shop floor vs mill

shop floor and mill both are nouns.

Word	Noun	Adjective	Verb	Adverb
shop floor	Yes	No	No	No
mill	Yes	No	Yes	No

shop floor (noun)	mill (noun)
workplace consisting of the part of a factory housing the machines	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

shop floor (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