Green’s Dictionary of Slang

a small, noisy child; synons. incl. chatter-bags, chatter-bladder, chatter-cart and (US) chatter-bones.

1772		Bridges (3rd edn) Burlesque Homer 350: He’d [...] spoke his mind because he reckon’d / Old Chatterbags would be his second.
1797		Bridges Burlesque Homer (4th edn) II 122: [as cit. 1772].
1859, 1860		Hotten Dict. of Modern Sl. etc.
1873		Sl. Dict.
1915		M.G. Hayden ‘Terms Of Disparagement’ in DN IV:iii 208: chatter-box, -basket, -bones, -cart, incessant talker. ‘You are such a chatter-box and never say anything either.’.

tea.

1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.

a machinegun or sub-machinegun.

1931		J. Wilstach Under Cover Man 8: Tracin’ that chattergun might mean a couple of square shooters ridin’ the thunderbolt.
1940		S. Sterling ‘Ten Carats of Lead’ in Black Mask Stories (2010) 228/2: Watch it. They got a chatter gun.
1969		D. Pendleton Executioner (1973) 16: Another chattergun had joined the action.
2003		R. Harding Outrider II Ch. 11: 🌐 Did he have three blades on his hip? And a shotgun? And a haul-ass car with a big chattergun on the back?

see separate entries.