Green’s Dictionary of Slang

1. an intimate companion, esp. as a fellow drinker and roisterer.

1601		Marston Jacke Drums Entertainment Act I: Come Timothy Twedle, tickle thy Pipe on the greene, as I haue tipled the Pot in the Seller, and the hey for the honor of High-gate, you old Troian.
1607		T. Heywood A Woman Killed with Kindness in Sturgess Three Elizabethan Domestic Tragedies (1969) 241: I’ll make him drunk if he be a Trojan.
1633		S. Marmion Fine Companion III iv: Heare me honest Trojan.
1660		J. Tatham Rump III i: I ha been a trusty Trojan, Sirs.
1691		N. Ward ‘The Poet’s Ramble after Riches’ in Writings (1704) 1: I Sing of neither Hogan Mogan / Of Ancient Greek or Trusty Trojan.
c.1698		B.E. Dict. Canting Crew n.p.: Trusty-Trojan, or Trusty-Trout, a sure Friend or Confident.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1746		W. Dunkin Parson’s Revels (2010) 107: Yet like a trusty Trojan true, / I fairly fill my Glass with you / And here you see me drink it Su / -Per Naculum.
1762		Bridges Homer Travestie (1764) I 148: But Venus [...] To save her trusty Trojan came.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Trusty Trojan [...] a true friend.
1811		Lex. Balatronicum [as cit. 1785].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1841		W.J. Neale Paul Periwinkle 451: ‘God bless you, my old friend,’ said the sturdy Trojan.
1867		M. Lemon Golden Fetters II 68: ‘Well, my Trojan,’ said Dick — he and Mr. Daw had become thus familiar.
1879		C.J. Kickham Knocknagow 219: ’Tis to the old cock I was talking. How goes it, my old Trojan?

2. a generally good fellow.

c.1595		Shakespeare Love’s Labour’s Lost V ii: Faith, Unless you play the honest Trojan, the poor wench is cast away: she’s quick.
1600		W. Kemp Nine Daies Wonder C ii n.p.: He was a kinde good fellow, a true Troyan; and if euer be my lucke to meete him at more leasure, Ile make him full amendes with a Cup full of Canarie .
1628		Ford Lover’s Melancholy IV ii: By your leave, gallants, I come to speak with a young lady, as they say, the old Trojan’s daughter of this house.
1640		Fletcher Night-Walker IIi i: Sam the Butler’s true, the Cooke a reverend Trojan.
1660		‘A Dialogue betwixt Tom and Dick’ in Rump Poems and Songs (1662) ii 189: Dost see that Jolly Lad? That’s he [...] There’s a true Trojan in his face.
1701		N. Ward ‘Battel without Bloodshed’ in Writings (1704) 121: The Wital, the Coward, the Trojan that’s Trusty.
1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 180: Trojan. A hardy indomitable person.
1845		J. Lindridge Sixteen-String Jack 117: You’d make a precious sight more than you’ve lost, my old Trojan.
1882		Bristol Magpie 14 Dec. 11/1: ‘Yes, shell out, me Trojan; shure it's money or your life’.
1913		J. London Valley of the Moon (1914) 338: She’s [...] a perfect Trojan during the jam and jelly season.
1916		J. Buchan Greenmantle (1930) 261: ‘You’re an old Trojan, Peter,’ I said.

3. a professional gambler.

1984

Partridge DSUE (8th edn) 1265: ca. 1805–40.