parchment vs sheepskin

parchment and sheepskin both are nouns.

Word	Noun	Adjective	Verb	Adverb
parchment	Yes	No	No	No
sheepskin	Yes	No	No	No

As nouns, parchment and sheepskin are synonyms defined as:

parchment and sheepskin: skin of a sheep or goat prepared for writing on

Other synonyms of parchment include lambskin.

parchment (noun)	sheepskin (noun)
skin of a sheep or goat prepared for writing on	a document certifying the successful completion of a course of study
a superior paper resembling sheepskin	tanned skin of a sheep with the fleece left on; used for clothing
	skin of a sheep or goat prepared for writing on