Green’s Dictionary of Slang

1. a boxing glove.

1842

Whip & Satirist of NY & Brooklyn (NY) 30 July n.p.: Some of whom [i.e. boxing fans] [...] wound up with a set-to with the ‘leathers’ .

2. anyone wearing leather leggings or breeches, e.g. a coachman.

1849		Thackeray Pendennis I 196: ‘Come along; jump in, old boy – go it, leathers!’ – and in this way Pen found himself in Mr. Spavin’s postchaise.
1894		(con. c.1850) G.A. Sala Things I Have Seen I 11: He had [...] an old-world look about him, inasmuch as he always wore leathers and top-boots.
1918		J.N. Hall High Adventure 11: A chap in leathers, who came down the drive. [Ibid.] 16: At the camp most of the men wear leathers.

3. in coaching, harness.

1876

‘Some Road Slang Terms’ in Malet Annals of the Road 389: 1. Of Harness Leathers...Harness.

4. leather garments, esp. as worn by motorcyclists; occas. in sing.

[1848		Bell’s Life in Sydney 26 Aug. 1/2: [H]is well fitting and beautifully cleaned ‘leathers’, and, top boot]s.
1969		I. Hebditch ‘Weekend’ unpub. thesis in Hewitt (2000) 133: I go round to get my mate Jack, he’s just got a new leather, two tone, nice.
1971		J. Mandelkau Buttons 38: Some of the old gang returned, wearing their leathers.
1980		(con. 1970) W. Sherman Times Square 31: ‘I’m rough trade tonight,’ he lisped [...] ‘I love your leathers.’.
1991		D. Jarman letter 25 June Smiling in Slow Motion (2000) 24: Manfred in his leathers with his new boyfriend from the East.
1996		P. Temple Bad Debts (2012) [ebook] Their leathers gleamed like otter skins.
2000		Indep. on Sun. Real Life 16 Jan. 8: Original biker leathers in colours that roar louder than a Honda.
2013		T. Black Ringer [ebook] n.p.: Two more biffers, both bald boys in black leathers.

5. (UK black) shoes.

1999

(con. 1979–80) A. Wheatle Brixton Rock (2004) 181: His shoes were discomforting him as the rims of his leathers almost crocodiled his ankles.

6. (UK black) gloves.

2018-20

T. Thorne (ed.) ‘Drill Slang Glossary’ at Forensic Linguistic Databank 🌐 Leathers - gloves.