disaccharide vs lactose

disaccharide and lactose both are nouns.

Word	Noun	Adjective	Verb	Adverb
disaccharide	Yes	No	No	No
lactose	Yes	No	No	No

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

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

Other hyponyms of disaccharide include milk sugar, malt sugar, maltose, saccharose, sucrose.

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