Green’s Dictionary of Slang

1. pistols; rarely in sing.; also attrib.

1587		W. Harrison Description of England in Oliphant New Eng. ii 2: Amongst the new substantives are snapper (pistol) butt-end [F&H].
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1809		G. Andrewes Dict. Sl. and Cant.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1834		(con. 1737–9) W.H. Ainsworth Rookwood (1857) 53: He always carried a lute [...] along with his snappers.
1834		‘Jack Downing’ Andrew Jackson 67: the gineral, gittin his hand loose found one of his snappers.
1859		Matsell Vocabulum.
1874		M. Clarke Term of His Natural Life (1897) 52: Once get the snapper chest, and we’re right as ninpenn’orth o’ hapence.
1881		Trumble Sl. Dict. (1890).
1895		Crowe Aus. Sl. Dict. 77: Snappers, firearms.

2. (US) beans.

1887

G. Davis Recoll. Sea-Wanderer 289: There are other terms in common use in the cabin and cook's galley [...] beans are tornadoes, snappers or band of music, and bean soup is snapper soup.

3. teeth, usu. false.

1923		Wodehouse Leave it to Psmith (1993) 372: This fellow understands my snappers.
1936		Wodehouse Laughing Gas n.p.: You shrink from entrusting your snappers to a strange dentist.
1956		‘Charles Raven’ Und. Nights 201: Wally, half asleep, takes a swig from the mug containing the Rabbi’s snappers.
1960		‘Lord Buckley’ Hiparama of the Classics 26: A crockodile put the snappers on him and they had to knock him in a hole.
1979		K. Bonfiglioli After You with the Pistol (1991) 283: He’d not got himself a set of dining-snappers off the National Health.
2006		Guardian G2 28 Mar. 4: My generation fondly expects to go to the grave with a full set of snappers.