Part of speech: Verb
talk indistinctly; usually in a low voice
Categories: Talk, Speak, Utter, Mouth, Verbalize, Verbalise
Part of speech: Verb
grind with the gums; chew without teeth and with great difficulty
Example: the old man had no teeth left and mumbled his food
Categories: Chew, Masticate, Manducate, Jaw
Mussitate, Maunder, Mutter, Mumble, Gum
The word "mumble" comes from Middle English momelen. Many other languages have similar words:
mum#Etymology 3 – A related word in the same word family.
Middle English had more flexible word order than Modern English because it retained more inflections.