Pony
WordNet
noun
(1) A range horse of the western United States
(2) Any of various breeds of small gentle horses usually less than five feet high at the shoulder
(3) An informal term for a racehorse
"He liked to bet on the ponies"
(4) A small glass adequate to hold a single swallow of whiskey
(5) A literal translation used in studying a foreign language (often used illicitly)