bumbler vs stumbler

bumbler and stumbler both are nouns.

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

As nouns, bumbler and stumbler are synonyms defined as:

bumbler and stumbler: someone who makes mistakes because of incompetence

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

bumbler (noun)	stumbler (noun)
someone who makes mistakes because of incompetence	a walker or runner who trips and almost falls
	someone who makes mistakes because of incompetence