bumbler vs bungler

bumbler and bungler both are nouns.

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

As nouns, bumbler and bungler are synonyms defined as:

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

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