milling machine vs miller

milling machine and miller both are nouns.

Word	Noun	Adjective	Verb	Adverb
milling machine	Yes	No	No	No
miller	Yes	No	No	No

As nouns, milling machine and miller are synonyms defined as:

milling machine and miller: machine tool in which metal that is secured to a carriage is fed against rotating cutters that shape it

milling machine (noun)	miller (noun)
machine tool in which metal that is secured to a carriage is fed against rotating cutters that shape it	any of various moths that have powdery wings
	machine tool in which metal that is secured to a carriage is fed against rotating cutters that shape it
	someone who works in a mill (especially a grain mill)