mumble vs maunder

mumble is a noun but maunder is not a noun.

Word	Noun	Adjective	Verb	Adverb
mumble	Yes	No	Yes	No
maunder	No	No	Yes	No

As verbs, mumble and maunder are synonyms defined as:

Other synonyms of mumble include mussitate, mutter.

mumble (noun)	maunder (noun)
a soft indistinct utterance

mumble (verb)	maunder (verb)
talk indistinctly; usually in a low voice	talk indistinctly; usually in a low voice
grind with the gums; chew without teeth and with great difficulty	speak (about unimportant matters) rapidly and incessantly
	wander aimlessly