Green’s Dictionary of Slang

lemon and sarse n.

(Aus.) the posterior, the buttocks.

1996

(con. 1964-65) B. Thorpe Sex and Thugs and Rock ’n’ Roll 8: ‘Her lemon!. . .Her lemon and sarse, my son! Her arse!’.

In phrases

give someone the lemon (sarse) (v.)

to dismiss from a job [rhy. sl. = arse n. (9)].

1989

R.G. Barratt ‘So Why Doesn’t Jack the Lad Get a Real Job?’ in What Do You Reckon (1997) [ebook] [T]he racist bastard gave me the lemon.