Green’s Dictionary of Slang

1. the anus.

1886

Burton ‘Terminal Essay’ in Arab Nights 182: Dr Tardieu [...] and Dr Adolph note a peculiar infundibuliform disposition of the ‘After’ and a smoothness and want of folds even before any abuse has taken place, together with the special forms of the male organs in confirmed pederasts [Simes:DLSS].

2. (Aus./US) afternoon.

1906		E. Dyson Fact’ry ’Ands 104: Iv yeh don’t do yer fair share iv yacker this after, I’ll punt ther slacks off yer.
1909		‘A “Push” Story’ in Bulletin (Sydney) 2 Sept. 17/1: [A] bunch uv barrackers are torn fr’m th’ ’ome circle. A pair uv Johns rumbled ’em away in th’ confinement coach [...] this arfter.
1927		Smith’s Wkly 20 Aug. 11/1: Slanguage. Time allowed: ’Arf the flamin’ after.
1934		J.H. O’Hara Appointment in Samarra 46: Tonight, or this after’, when Ed showed up at the Apollo, he probably would be in a bad humour.
1939		J. Mulgan Man Alone 235: Boss wants us to get the hay in up top this after [OED].
1947		H. Drake-Brockman Fatal Days n.p.: Did you see Mr Scrown this after, Les?