glucose vs grape sugar

glucose and grape sugar both are nouns.

Word	Noun	Adjective	Verb	Adverb
glucose	Yes	No	No	No
grape sugar	Yes	No	No	No

As nouns, grape sugar is a hyponym of glucose; that is, grape sugar is a word with a more specific, narrower meaning than glucose:

glucose: a monosaccharide sugar that has several forms; an important source of physiological energy
grape sugar: an isomer of glucose that is found in honey and sweet fruits

Other hyponyms of glucose include glucosamine, corn sugar, dextroglucose, dextrose, blood glucose, blood sugar.

glucose (noun)	grape sugar (noun)
a monosaccharide sugar that has several forms; an important source of physiological energy	an isomer of glucose that is found in honey and sweet fruits