bumbler vs blunderer

bumbler and blunderer both are nouns.

Word	Noun	Adjective	Verb	Adverb
bumbler	Yes	No	No	No
blunderer	Yes	No	No	No

As nouns, bumbler and blunderer are synonyms defined as:

bumbler and blunderer: someone who makes mistakes because of incompetence

Other synonyms of bumbler include botcher, bungler, butcher, fuckup, fumbler, sad sack, stumbler.

bumbler (noun)	blunderer (noun)
someone who makes mistakes because of incompetence	someone who makes mistakes because of incompetence