fructose vs fruit sugar

fructose and fruit sugar both are nouns.

Word	Noun	Adjective	Verb	Adverb
fructose	Yes	No	No	No
fruit sugar	Yes	No	No	No

As nouns, fructose and fruit sugar are synonyms defined as:

fructose and fruit sugar: a simple sugar found in honey and in many ripe fruits

Other synonyms of fructose include laevulose, levulose.

fructose (noun)	fruit sugar (noun)
a simple sugar found in honey and in many ripe fruits	a simple sugar found in honey and in many ripe fruits