milk sugar vs disaccharide

milk sugar and disaccharide both are nouns.

Word	Noun	Adjective	Verb	Adverb
milk sugar	Yes	No	No	No
disaccharide	Yes	No	No	No

As nouns, disaccharide is a hypernym of milk sugar; that is, disaccharide is a word with a broader meaning than milk sugar:

milk sugar: a sugar comprising one glucose molecule linked to a galactose molecule; occurs only in milk
disaccharide: any of a variety of carbohydrates that yield two monosaccharide molecules on complete hydrolysis

milk sugar (noun)	disaccharide (noun)
a sugar comprising one glucose molecule linked to a galactose molecule; occurs only in milk	any of a variety of carbohydrates that yield two monosaccharide molecules on complete hydrolysis