What is "alycidon"

Alycidon (1945–1963) was a British Thoroughbred racehorse who was described as "one of the greatest stayers in history". In a career which lasted from the autumn of 1947 until September 1949 he ran seventeen times and won eleven races. He was the second best British three-year-old of his generation, when he finished second to Black Tarquin in the St. Leger Stakes. He was undefeated in his remaining seven races, defeating Black Tarquin in the 1949 Ascot Gold Cup and going on to win the Stayers' Triple Crown. After his retirement from racing he became the Leading sire in Great Britain & Ireland in 1955, despite having low fertility and a relatively short career at stud.