bumble vs stumble

bumble is not a noun while stumble is a noun.

Word	Noun	Adjective	Verb	Adverb
bumble	No	No	Yes	No
stumble	Yes	No	Yes	No

As verbs, bumble and stumble are synonyms defined as:

Other synonyms of bumble include falter.

bumble (noun)	stumble (noun)
	an unsteady uneven gait
	an unintentional but embarrassing blunder

bumble (verb)	stumble (verb)
speak haltingly	make an error
walk unsteadily, tripping repeatedly	miss a step and fall or nearly fall
make a mess of, destroy or ruin	walk unsteadily, tripping repeatedly
	encounter by chance