Green’s Dictionary of Slang

1. style, fashion; usu. as in twig, smartly or fashionably dressed.

1794		Sporting Mag. May IV 122/1: A merry grig – thus fix my twig – / And roguish cock my hat.
1811		Lex. Balatronicum n.p.: The cove is togged in twig; the fellow is dressed in the fashion.
1821		‘An Amateur’ Real Life in London I 341: The pride of becoming an accomplished whip — to know how to turn a corner in style — tickle Snarler in the ear — cut up the yelper — take out a fly’s eye in bang-up twig.
1829		Reading Mercury 28 Dec. 3/5: Will it find me in ‘prime twig’ or in tatters?
1830		Bell’s Life in London 17 Oct. 3/1: Harry Jones has been waiting on Adrian, who is represented as being in ‘prime twig’.
1834		(con. 1737–9) W.H. Ainsworth Rookwood (1857) 178: Ne’er was there seen such a dashing prig, / With my strummel faked in the newest twig.
1848		Flash Dict. in Sinks of London Laid Open 109: Grand twig, in prime style.
1859, 1860		Hotten Dict. of Modern Sl. etc.
1864, 1867, 1870		Hotten Sl. Dict. 263: TWIG, style, à la mode; ‘get your strummel faked in twig,’ i.e., have your hair dressed in style; prime twig, in good order and high spirits.
1881		Newcastle Courant 2 Sept. 6/5: Fond of dressy display, he usually showed himself [...] in the ‘newest twig,’ and with several ‘fawnies’ on his fingers.
1895		Crowe Aus. Sl. Dict. 90: Twig, [...] style or condition,‘as in prime twig;’ grand condition, etc.

2. (orig. boxing) condition, fettle, spirits; often as in fine twig

1819		‘One of the Fancy’ Tom Crib’s Memorial to Congress 8: Never since the renown’d days of BROUGHTON and FIGG / Was the Fanciful World in such very prime twig.
1820		Jack Randall’s Diary 62: In search of lark, or some delicious gig The mind delights in, when ’tis in prime twig Some precious piece of laughter-loving fun.
1841		Era (London) 28 Mar. 10/3: Newmarket [...] Snow drop (in good style) [...] Joachim (in prime twig).
1853		N.Y. Clipper 10 Sept. 1/4: The Black [...] rallied in prime twig.
1864, 1867, 1870		Hotten Sl. Dict. 263: TWIG, style, à la mode; ‘get your strummel faked in twig,’ i.e., have your hair dressed in style; prime twig, in good order and high spirits.
1895		Crowe Aus. Sl. Dict. see sense 1.

3. (also tuig) a stylish (young) man.

c.1805		‘The Wig Gallery’ in Jovial Songster 30: Be of the ton a natty sprig, / The thing, the tippy, and the twig.
1821		D. Haggart Autobiog. 15: I was rumbling the cloys of the tuigs.
1834		Ely’s Hawk and Buzzard (N.Y.) 21 June 1/1: There were many more conspicuous twigs there. [Ibid.] 3/4: The decent part of the congregation [...] feel themselves much annoyed by these hopeful twigs.