computing vs undecideable

computing is a noun but undecideable is not a noun.

Word	Noun	Adjective	Verb	Adverb
computing	Yes	No	No	No
undecideable	No	Yes	No	No

computing (noun)	undecideable (noun)
the procedure of calculating; determining something by mathematical or logical methods
the branch of engineering science that studies (with the aid of computers) computable processes and structures

computing (adjective)	undecideable (adjective)
	not capable of being decided as following or not following from the axioms of a logical system