milk whey vs whey

milk whey and whey both are nouns.

Word	Noun	Adjective	Verb	Adverb
milk whey	Yes	No	No	No
whey	Yes	No	No	No

As nouns, milk whey and whey are synonyms defined as:

milk whey and whey: the serum or watery part of milk that is separated from the curd in making cheese

milk whey (noun)	whey (noun)
the serum or watery part of milk that is separated from the curd in making cheese	watery part of milk produced when raw milk sours and coagulates
	the serum or watery part of milk that is separated from the curd in making cheese