What is "wollow"

Wollow (1973 – after 1997) was an Irish-bred, British-trained Thoroughbred racehorse and sire. In a career that lasted from summer 1975 to October 1976 he ran eleven times and won nine races. In 1975 he was rated the best two-year-old in Britain by a margin of five pounds and the following spring he won the Classic 2000 Guineas. He was undefeated in six races when starting favourite for the 1976 Epsom Derby but finished unplaced. Wollow won three more important races before his retirement later that year. He made little impact at stud and was exported to Japan in 1981.