muskrat vs fur

muskrat and fur both are nouns.

Word	Noun	Adjective	Verb	Adverb
muskrat	Yes	No	No	No
fur	Yes	No	No	No

As nouns, fur is a hypernym of muskrat; that is, fur is a word with a broader meaning than muskrat:

Other hypernyms of muskrat include pelt.

muskrat (noun)	fur (noun)
beaver-like aquatic rodent of North America with dark glossy brown fur	dense coat of fine silky hairs on mammals (e.g., cat or seal or weasel)
the brown fur of a muskrat	a garment made of animal pelts or synthetic fur
	the dressed hairy coat of a mammal