donut fryer vs deep fryer

donut fryer and deep fryer both are nouns.

Word	Noun	Adjective	Verb	Adverb
donut fryer	Yes	No	No	No
deep fryer	Yes	No	No	No

As nouns, deep fryer is a hypernym of donut fryer; that is, deep fryer is a word with a broader meaning than donut fryer:

donut fryer: a machine used to fry large quantities of doughnuts at once.
deep fryer: A kitchen appliance for deep frying; its size depends on intended use.

Other hypernyms of donut fryer include machine, deep fat fryer, frier, fryer, fryolator.

donut fryer (noun)	deep fryer (noun)
a machine used to fry large quantities of doughnuts at once.	A kitchen appliance for deep frying; its size depends on intended use.