What is "topsider"

n. A boat shoe

Topsider (1974–1992) was an American Thoroughbred racehorse. He was a bay son of the great Northern Dancer and the very speedy racing mare Drumtop. 1

Topsider won eight races from eighteen career starts, including the Sport Page Handicap at Aqueduct Racetrack in New York City. 2 In another of his wins he set a new track record of 1:14 2/5 for 6½ furlongs at Saratoga Race Course.

When his racing career was over, Topsider was sent to Claiborne Farm in Kentucky where became a significant sire whose offspring won more than $18 million in racing. 3 Among his best were two Champions: North Sider, the 1987 American Champion Older Female Horse, and Salse, a Champion Three-Year-Old in France. Topsider stood his entire career at Claiborne Farm and died there on October 18, 1992 as a result of a hernia in his diaphragm.