mill vs steel factory

mill and steel factory both are nouns.

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

As nouns, steel factory is a hyponym of mill; that is, steel factory is a word with a more specific, narrower meaning than mill:

mill: a plant consisting of one or more buildings with facilities for manufacturing
steel factory: a factory where steel is made

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

mill (verb)	steel factory (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