handiness vs availability

handiness and availability both are nouns.

Word	Noun	Adjective	Verb	Adverb
handiness	Yes	No	No	No
availability	Yes	No	No	No

As nouns, handiness and availability are synonyms defined as:

Other synonyms of handiness include accessibility, availableness.

handiness (noun)	availability (noun)
the quality of being at hand when needed	the quality of being at hand when needed
skillfulness with the hands