coat vs sheepskin coat

coat and sheepskin coat both are nouns.

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

As nouns, sheepskin coat is a hyponym of coat; that is, sheepskin coat is a word with a more specific, narrower meaning than coat:

coat: an outer garment that has sleeves and covers the body from shoulder down; worn outdoors
sheepskin coat: a coat made of sheepskin

coat (noun)	sheepskin coat (noun)
growth of hair or wool or fur covering the body of an animal	a coat made of sheepskin
an outer garment that has sleeves and covers the body from shoulder down; worn outdoors
a thin layer covering something

coat (verb)	sheepskin coat (verb)
cover or provide with a coat
put a coat on; cover the surface of; furnish with a surface
form a coat over