stumbler vs fumbler

stumbler and fumbler both are nouns.

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

As nouns, stumbler and fumbler are synonyms defined as:

stumbler and fumbler: someone who makes mistakes because of incompetence

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

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