Green’s Dictionary of Slang

1. the anus; the buttocks.

1967		‘Whisper All Aussie Dict.’ in Kings Cross Whisper (Sydney) xxxii 7/1: blurter: Posterior.
1985		B. Humphries Traveller’s Tool 90: A kangaroo with a reel of fillum stuck up its blurter.
1988		McGill Dict. of Kiwi Sl. 17/1: blurter anus; from association with ‘blurt’, a sudden emission of breath.
1989		R.G. Barrett Boys from Binjiwunyawunya 164: Those old lags [...] They’d be into your blurter before you could whistle.
1996		J. Byrell Lairs, Urgers & Coat-Tuggers 234: ‘Any win is better than a boot up the blurter, eh Flea?’.
2002		R.G. Barrett Mystery Bay Blues 24: Shuffling round Bondi, like Marriane [sic] Faithfull with an axe-handle stuck up her blurter.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].

2. a fart.

2000

M. Manning Get Your Cock Out 4: Mincey raised a cheek and let fly a blurter.