watershed vs water parting

watershed and water parting both are nouns.

Word	Noun	Adjective	Verb	Adverb
watershed	Yes	No	No	No
water parting	Yes	No	No	No

As nouns, watershed and water parting are synonyms defined as:

watershed and water parting: a ridge of land that separates two adjacent river systems

Other synonyms of watershed include divide.

watershed (noun)	water parting (noun)
an event marking a unique or important historical change of course or one on which important developments depend	a ridge of land that separates two adjacent river systems
a ridge of land that separates two adjacent river systems
the entire geographical area drained by a river and its tributaries; an area characterized by all runoff being conveyed to the same outlet