Green’s Dictionary of Slang

1. angry.

1853		Dickens Bleak House (1991) 353: It would cheer him up more than anything if I could make him a little waxy with me.
1864, 1867, 1870		Hotten Sl. Dict.
1873		‘Cuthbert Bede’ Little Mr. Bouncer 34: Don’t [...] get waxy, and make yourself as red as your face.
1888		J. Runciman Chequers 80: Never mind, I was waxy when I done it.
1895		Crowe Aus. Sl. Dict. 93: Wax, a rage [...] waxy, cross.
1896		G.M. Fenn Sappers and Miners 46: Made him a bit waxy [...] but he’ll come round to my way of thinking yet.
1904		Sydney Sportsman (Surry Hills, NSW) 14 Sept. 3/4: She waxes awfully waxy over the ridiculous and even contemptible description of women’s clothes in any man’s novel.
1913		A. Lunn Harrovians 9: Don’t get waxy; I was only telling you for your own good.
1918		Butterfly and Firefly 23 Nov. 8: My! he was waxy when he found he was my prisoner.
1940		M. Marples Public School Slang 3: ANGRY [...] waxy, in a wax.
1953		J. Franklyn Cockney 285: The person being ‘taken on’ might get ratty, or waxy.

2. (UK black) arrogant, aggressive.

2016

Harlem Spartans ‘Hazards’ 🎵 True, I'm way too wassy / Before I smoke, I used to step with bassy (bassy).