butter vs yak butter

butter and yak butter both are nouns.

Word	Noun	Adjective	Verb	Adverb
butter	Yes	No	Yes	No
yak butter	Yes	No	No	No

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

butter: an edible emulsion of fat globules made by churning milk or cream; for cooking and table use
yak butter: butter made from yaks' milk

butter (noun)	yak butter (noun)
an edible emulsion of fat globules made by churning milk or cream; for cooking and table use	butter made from yaks' milk
a fighter who strikes the opponent with his head

butter (verb)	yak butter (verb)
spread butter on