What is "signorinetta"

Signorinetta (1905–1928) was a British Thoroughbred racehorse and broodmare. In a racing career which lasted from 1907 to 1908 she ran thirteen times and won three races. Although most of her career was undistinguished she showed outstanding form at Epsom in the summer of 1908 when she won both the Epsom Derby and the Epsom Oaks. Trained by her eccentric and unconventional Italian owner, she won the Derby as a 100/1 outsider, creating one of the biggest upsets in racing history. After her retirement from racing she had some success as a broodmare.