diploma vs sheepskin

diploma and sheepskin both are nouns.

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

As nouns, diploma and sheepskin are synonyms defined as:

diploma and sheepskin: a document certifying the successful completion of a course of study

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