lemony vs tart

lemony is not a noun while tart is a noun.

Word	Noun	Adjective	Verb	Adverb
lemony	No	Yes	No	No
tart	Yes	Yes	No	No

As adjectives, lemony and tart are synonyms defined as:

Other synonyms of lemony include lemonlike, sourish, tangy.

lemony (noun)	tart (noun)
	a small open pie with a fruit filling
	a pastry cup with a filling of fruit or custard and no top crust
	a woman who engages in sexual intercourse for money

lemony (adjective)	tart (adjective)
tasting sour like a lemon	tasting sour like a lemon
	harsh