primogenitor vs ascendent

primogenitor and ascendent both are nouns.

Word	Noun	Adjective	Verb	Adverb
primogenitor	Yes	No	No	No
ascendent	Yes	Yes	No	No

As nouns, ascendent is a hypernym of primogenitor; that is, ascendent is a word with a broader meaning than primogenitor:

primogenitor: an ancestor in the direct line
ascendent: someone from whom you are descended (but usually more remote than a grandparent)

Other hypernyms of primogenitor include ancestor, antecedent, ascendant, root.

primogenitor (noun)	ascendent (noun)
an ancestor in the direct line	someone from whom you are descended (but usually more remote than a grandparent)
	position or state of being dominant or in control

primogenitor (adjective)	ascendent (adjective)
	tending or directed upward
	most powerful or important or influential