Noun. An obstreperous mouth.
Hark! Shut your obstropolos.
– Ulysses, James Joyce (1922)
Leave it to the OED to give you a definition that you probably need to look up.
Obstreperous: adj. Clamorous, noisy, vociferous. Give yourself a pat on the back if you already knew obstreperous. You are a true word-nerd.
This could be a good word to use when you feel like coming off like a total snob to someone who just won’t be quiet. Just say, “Shut your obstropolos,” and you’ll no longer be plagued by their presence. Works well for co-workers, in-laws, and tele-marketers.