grinder vs machinery

grinder and machinery both are nouns.

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

As nouns, machinery is a hypernym of grinder; that is, machinery is a word with a broader meaning than grinder:

grinder (noun)	machinery (noun)
a machine tool that polishes metal	machines or machine systems collectively
machinery that processes materials by grinding or crushing	a system of means and activities whereby a social institution functions
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