Green’s Dictionary of Slang

a horse, spec. any animal which has its tail cropped square; also attrib., thus (Aus.) bang-tail muster, a round-up of cattle during which the tuft at the end of the tail is cut straight across as the cattle are counted; thus bang-tail(ed) adj., cut square.

[1808		Sporting Mag. Jan. 130: Alphabetical List of the Winning Horses in 1807 [...] Bangtail].
[1812		Edinburgh Rev. 23 Oct. 258/1: Denghien, an entire horse, aged, colour brown, got by Bangtail by Highflyer, dam by Ruler].
1839		Sporting Rev. 341: Captain Harbord, on Wildgoose, and myself on Cigar, a strong horse of Lord Suffield's, thought nothing of it, but where were the baronet and his friend, on their bang-tail weeds?
1853		R.S. Surtees Mr Sponge’s Sporting Tour 4: His practised eye is not to be imposed upon [...] by the blandishments of the bang-tail.
1861		T. Hughes Tom Brown at Oxford (1880) 51: [of fishing flies] ‘These bang-tailed little sinners any good?’ said Drysdale, throwing some cock-a-bondies across the table.
1887		W. Tyrwhitt New Chum in the Queensland Bush 61: Every third or fourth year on a cattle station, they have what is called a ‘bang tail muster’; that is to say, all the cattle are brought into the yards, and have the long hairs at the end of the tail cut off square.
1902		‘Curlew‘ ‘Boko‘ in Bulletin Reciter n.p.: The day we got the buster was just after bangtail muster.
1914		Ade ‘The New Fable of Susan and the Daughter’ in Ade’s Fables 228: A rubber-tired Victoria, drawn by two expensive Bang-Tails in jingly Harness.
1917		Van Loan ‘Sanguinary Jeremiah’ in Old Man Curry 143: It was the last race of the season [...] and good-bye to the bangtails for another year.
1923		H.C. Witwer Fighting Blood 214: ‘What do you think of Knight Errant in the Brooklyn Handicap?’ I ask him [...] ‘Hey, listen,’ says Nate. ‘Lay off the bang-tails, kid.’.
1926		J. Doone Timely Tips For New Australians 15: BANG-TAIL MUSTER.—A muster of cattle in which the hairy end of each one’s tail is cut off to show it has been counted.
1929		H.C. Witwer Yes Man’s Land 154: The bangtails had me in hock for my pajamas.
1934		S. Walker City Editor 99: ‘Eddie!’ whinnied Daley, the distraught worshipper of the bang-tails. ‘Eddie! Phar Lap is dead!’.
1944		J. Archibald ‘Downed on the Farm’ in Ten Detective Aces Nov. 🌐 [...] tipping the cops off to a bangtail betting layout in the Hotel Quinsey.
1945		T. Thursday ‘You Gotta Have Luck’ in Popular Sports Jan. 🌐 On the morrow he would go to Hialeah, win some dough on the bangtails, and have one ritzy time.
1951		E. Hill Territory 391: The buyers have asked for a bang-tail.
1961		J. Scarne Complete Guide to Gambling.
1968		W.S. Hoffman Loser 11: ‘[M]y gambling goals had been rather modest. ‘Two thousand,’ I once told another bangtail buff, ‘and I'll quit’.
1989		K. Dunn Geek Love 335: Here’s the bang-tail filly again.
1994		R. Stookey Kinsella’s Man 238: If you ate a bit of this now and then you’d be able to whip some sense into that little bangtail of yours.
1997		Share Slanguage 12/2: bangtail Racehorse of questionable ability.
2004–06		S.A. MacBurnie at Omnificent Eng. Dict. in Limerick Form 🌐 A bangtail’s no more than a horse / That will race on a track or a course.