E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Abate (2 syl.)
means properly to knock down. (French, abattre, whence a battue, i.e., wholesale destruction of game; O.E. a beátan.)
Abate, in horsemanship, is to perform well the downward motion. A horse is said to abate when, working upon curvets, he puts or beats down bòth his hind legs to the ground at once, and keeps exact time.