mouth-watering vs savory

mouth-watering is not a noun while savory is a noun.

Word	Noun	Adjective	Verb	Adverb
mouth-watering	No	Yes	No	No
savory	Yes	Yes	No	No

As adjectives, mouth-watering and savory are synonyms defined as:

Other synonyms of mouth-watering include savoury.

mouth-watering (noun)	savory (noun)
	either of two aromatic herbs of the mint family
	an aromatic or spicy dish served at the end of dinner or as an hors d'oeuvre
	any of several aromatic herbs or subshrubs of the genus Satureja having spikes of flowers attractive to bees
	dwarf aromatic shrub of Mediterranean regions

mouth-watering (adjective)	savory (adjective)
having a pleasant taste	morally wholesome or acceptable
	having a pleasant taste
	having an agreeably pungent taste