ineptitude vs ineptness

ineptitude and ineptness both are nouns.

Word	Noun	Adjective	Verb	Adverb
ineptitude	Yes	No	No	No
ineptness	Yes	No	No	No

As nouns, ineptitude and ineptness are synonyms defined as:

ineptitude and ineptness: unskillfulness resulting from a lack of training

Other synonyms of ineptitude include awkwardness, clumsiness, maladroitness, slowness.

ineptitude (noun)	ineptness (noun)
having no qualities that would render it valuable or useful	the quality of having the wrong properties for a specific purpose
unskillfulness resulting from a lack of training	unskillfulness resulting from a lack of training