fox grape vs slipskin grape

fox grape and slipskin grape both are nouns.

Word	Noun	Adjective	Verb	Adverb
fox grape	Yes	No	No	No
slipskin grape	Yes	No	No	No

As nouns, slipskin grape is a hypernym of fox grape; that is, slipskin grape is a word with a broader meaning than fox grape:

fox grape: purplish-black wild grape of the eastern United States with tough skins that slip easily from the flesh; cultivated in many varieties
slipskin grape: a grape whose skin slips readily from the pulp

fox grape (noun)	slipskin grape (noun)
purplish-black wild grape of the eastern United States with tough skins that slip easily from the flesh; cultivated in many varieties	a grape whose skin slips readily from the pulp
native grape of northeastern United States; origin of many cultivated varieties e.g. Concord grapes