bungle vs stumble

bungle and stumble both are nouns.

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

As nouns, stumble is a hyponym of bungle; that is, stumble is a word with a more specific, narrower meaning than bungle:

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

bungle (verb)	stumble (verb)
spoil by behaving clumsily or foolishly	make an error
make a mess of, destroy or ruin	miss a step and fall or nearly fall
	walk unsteadily, tripping repeatedly
	encounter by chance