bangtail

The tail of a horse or cow, allowed to grow out and then trimmed horizontally so as to form a tassel; a horse or cow having such a tail.

1851, Turning Out a Bagman: A Legend of Brighton Downs, in Charles Dickens, William Harrison Ainsworth, Albert Smith Bentley's Miscellany, Volume XXIX, page 259, Two lean, ewe-necked, clipt chestnuts, tucked up in the ribs, with hard work and bad feeding, but with such flowing bang-tails as at once stamped them in the eyes of our friends as “ out-and-out ” thorough-breds—were led up and down by John. […] The bang-tails, no doubt, supposing themselves out for their usual “airing,” put themselves in the regular side-long position, and struck at once into a sort of hectic canter ; a particular movement, peculiar to Brighton bang-tails, and adapted to the most innocent equestrian.

1903, Tom Collins (Joseph Furphy), Such Is Life: Being Certain Extracts from the Diary of Tom Collins, 2004, page 68, "And did you see a dark chestnut horse; bang tail; star and snip; white hind feet; saddle and bridle on?" I asked.

A racehorse.

“Eddie!” whinnied Daley, the distraught worshipper of the bang-tails. “Eddie! Phar Lap is dead!”

Americans bet $5,000,000,000 a year on the galloping bangtails.

A prostitute.

An envelope with a perforated flap on which promotional material is printed; the flap on such an envelope.

To shear off the hair horizontally at the end of a cow or horse's tail.