stumble vs boo-boo

stumble and boo-boo both are nouns.

Word	Noun	Adjective	Verb	Adverb
stumble	Yes	No	Yes	No
boo-boo	Yes	No	No	No

As nouns, boo-boo is a hypernym of stumble; that is, boo-boo is a word with a broader meaning than stumble:

Other hypernyms of stumble include bloomer, blooper, blunder, boner, botch, bungle, flub, foul-up, fuckup, pratfall.

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

stumble (verb)	boo-boo (verb)
make an error
miss a step and fall or nearly fall
walk unsteadily, tripping repeatedly
encounter by chance