n.
 (pl. ponies)
   - a horse of a small breed, especially one below 15 hands (or 14 hands 2 inches). 
▸
(the ponies)
 informal, chiefly N. Amer. racehorses.
 - informal a small glass or measure of alcoholic drink.
 - Brit. informal twenty-five pounds sterling.
 
v.
 
(
pony something up)
 
N. Amer. informal hand over a sum of money, especially to settle an account.
 
  Etymology
  C17: prob. from Fr. poulenet ‘small foal’.