Green’s Dictionary of Slang

a beating, a thrashing.

1853		T. Haliburton Sam Slick’s Wise Saws I 99: I must say the crittur deserves a tannin’ most richly.
1864		A.F. Hill Our Boys 30: You may think yourself lucky, this time, that I don’t give you a tanning.
1894		Mirror of Life 21 July 3/3: [S]ome hireling [...] will endeavour to perform the functions of treating us to a good ‘tanning’ down.
1914		‘Ian Hay’ Lighter Side of School Life 185: I once got off a tanning by asking him how many times he had been Head of the River.
1929		Hull Dly Mail 17 June 10/2: He had ‘taken some tannings in his time’.
1935		(con. 1920s) McArthur & Long No Mean City 267: You could give this fellow a tanning aw right.
1950		C. Harris Three-Ha’Pence to the Angel 104: Ain’t too old for a tanning, neither.
1958		(con. 1940s) B. Behan Borstal Boy 145: I’d have taken down your pants and given you a good tanning.
1979		M. Matshoba Call Me Not A Man ix: The new principal [...] sneaked up on us and gave us tannings for the slightest transgression.