Green’s Dictionary of Slang

a fool, a clumsy, noisy fellow.

1650		Milton Defence of the People of England (1692) Pref. xxi: We had a discreet and intelligent Adversary, and not such a hair-brain’d Blunderbuss as you, to deal with.
1694		J. Eachard (trans.) Plautus’s Comedies Pref. a 4: If any Man can shew me a greater Lyer, or a more bragging Coxcomb than this Blunderbuss, he shall take me, make me his Slave.
1704		N. Ward Frolic to Horn Fair 14: These sort of Sea Monsters [...] had the right Knack of Coaxing these Quarter-Deck-Blunderbuisses out of their Farthings and Half-pence.
1729		T. Woolston Sixth Discourse on Miracles 50: No wise Man hardly ever reprehends a Blunderbuss for his Bull, any other way, than by laughing at him.
1730		J. Miller Humours of Oxford I i: The sight of that Blunderbuss bodes me no good.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict.
1771		Smollett Humphrey Clinker (1925) I 138: He damns all the other writers of the age [...] One is a blunderbuss, as being a native of Ireland; another a half-starved louse of literature, from the banks of the Tweed.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Blunderbuss. [...] a stupid, blundering fellow.
1809		G. Andrewes Dict. Sl. and Cant.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1835		G. Kent Modern Flash Dict. 6: Blunderbuss – a stupid ignorant fellow.
1848		Flash Dict. in Sinks of London Laid Open [as cit. 1835].
1859		Matsell Vocabulum 13: blunderbuss. An ignorant, blustering fellow.
1868		L.M. Alcott Little Women I 51: Oh dear! what a blunderbuss I am!
1895		Crowe Aus. Sl. Dict. 10: Blunderbuss, an ignorant blowhard.
1899		Boy’s Own Paper 13 May 518: ‘Yah! Who muddles everything?’ whispered Sniff. ‘Old Blunderbust!’.
1910		Richmond Climax (KY) 23 Feb. 3/4: The foreman [...] applied to him such terms as sleepy-head, idiot, blunderbuss.
1911		G. Stratton-Porter Harvester 518: ‘You puddin’ head! You blunderbuss!’ cried Granny.
1967–8		Baker et al. CUSS 84: Blunder bust A person who always does the wrong thing.