bangtail

1. A racehorse.
2. A detachable extension to the back of an envelope, having a perforated edge and special marketing information or an order form on it.

[BANG², short hair + TAIL¹.]

Promotional envelope with a perforated flap that can be removed and used as an order form. Bangtail envelopes are frequently used for film development promotion inserts in newspapers or magazines. See also wallet flap.

The name given to a horse or cow in which the long hairs on the tail are sheared off horizontally, in the horse level with the hocks. Done partly for show, in cattle mainly as a mark that the cattle have been handled and the usual operations of castration or spaying have been performed. Called also banged tail.

The noun has one meaning:

Meaning #1: a horse bred for racing
  Synonyms: racehorse, race horse