directionality vs directional

directionality is a noun but directional is not a noun.

Word	Noun	Adjective	Verb	Adverb
directionality	Yes	No	No	No
directional	No	Yes	No	No

directionality (noun)	directional (noun)
the property of a microphone or antenna of being more sensitive in one direction than in another
the property of being directional or maintaining a direction

directionality (adjective)	directional (adjective)
	relating to or indicating directions in space
	relating to direction toward a (nonspatial) goal
	showing the way by conducting or leading; imposing direction on