Green’s Dictionary of Slang

1. (also dagan, dagen) a sword.

c.1698		B.E. Dict. Canting Crew n.p.: Degen c. a Sword. Nimm the Degen, c. steal the Sword, or whip it from the Gentleman’s Side.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
c.1750–1882		B.M. Carew Life and Adventures.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: degen, or dagen, a sword; (cant) nim the degen, steal the sword. Dagen is Dutch for a sword.
a.1790		H.T. Potter New Dict. Cant (1795) n.p.: degen, or dagen a sword.
1809		G. Andrewes Dict. Sl. and Cant.
1811		Lex. Balatronicum.
1828		Lytton Pelham III 333: Tip him the degen, Fib, fake him through and through; if he pikes, we shall all be scragged.
1835		G. Kent Modern Flash Dict. 11: Dagen – a sword.
1848		Flash Dict. in Sinks of London Laid Open [as cit. 1835].
c.1850		Duncombe New and Improved Flash Dict.
1859		Matsell Vocabulum 24: dagan A sword.

2. an artful person [suggests play on knowing blade].

1937–84

Partridge DSUE (1984) 298/2: C.19.