cutter vs diner

cutter and diner both are nouns.

Word	Noun	Adjective	Verb	Adverb
cutter	Yes	No	No	No
diner	Yes	No	No	No

As nouns, diner is a hypernym of cutter; that is, diner is a word with a broader meaning than cutter:

cutter (noun)	diner (noun)
a cutting implement; a tool for cutting	a passenger car where food is served in transit
a boat for communication between ship and shore	a restaurant that resembles a dining car
a sailing vessel with a single mast set further back than the mast of a sloop	a person eating a meal (especially in a restaurant)
someone whose work is cutting (as e.g. cutting cloth for garments)
someone who carves the meat
someone who cuts or carves stone