incompetent vs bungling

incompetent is a noun but bungling is not a noun.

Word	Noun	Adjective	Verb	Adverb
incompetent	Yes	Yes	No	No
bungling	No	Yes	No	No

As adjectives, incompetent and bungling are synonyms defined as:

Other synonyms of incompetent include clumsy, fumbling.

incompetent (noun)	bungling (noun)
someone who is not competent to take effective action

incompetent (adjective)	bungling (adjective)
not qualified or suited for a purpose	lacking physical movement skills, especially with the hands
legally not qualified or sufficient	showing lack of skill or aptitude
not doing a good job
not meeting requirements
showing lack of skill or aptitude