flexibleness vs flexible

flexibleness is a noun but flexible is not a noun.

Word	Noun	Adjective	Verb	Adverb
flexibleness	Yes	No	No	No
flexible	No	Yes	No	No

flexibleness (noun)	flexible (noun)
the property of being flexible; easily bent or shaped
the quality of being adaptable or variable

flexibleness (adjective)	flexible (adjective)
	able to flex; able to bend easily
	capable of being changed
	making or willing to make concessions
	able to adjust readily to different conditions
	bending and snapping back readily without breaking