machinery vs grinder

machinery and grinder both are nouns.

Word	Noun	Adjective	Verb	Adverb
machinery	Yes	No	No	No
grinder	Yes	No	No	No

As nouns, grinder is a hyponym of machinery; that is, grinder is a word with a more specific, narrower meaning than machinery:

Other hyponyms of machinery include enginery, technology, mill, milling machinery.

machinery (noun)	grinder (noun)
machines or machine systems collectively	a machine tool that polishes metal
a system of means and activities whereby a social institution functions	machinery that processes materials by grinding or crushing
	grinding tooth with a broad crown; located behind the premolars
	a large sandwich made of a long crusty roll split lengthwise and filled with meats and cheese (and tomato and onion and lettuce and condiments); different names are used in different sections of the United States