declivity vs descent

declivity and descent both are nouns.

Word	Noun	Adjective	Verb	Adverb
declivity	Yes	No	No	No
descent	Yes	No	No	No

As nouns, declivity and descent are synonyms defined as:

Other synonyms of declivity include declension, declination, decline, downslope, fall.

declivity (noun)	descent (noun)
a downward slope or bend	the act of changing your location in a downward direction
	properties attributable to your ancestry
	a movement downward
	the hereditary derivation of an individual
	a downward slope or bend
	the kinship relation between an individual and the individual's progenitors