The name "greyhound" is generally believed to come from the Old English grighund. "Hund" is traced to the modern "hound", but the meaning of "grig" is undetermined, other than in reference to dogs in Old English and Norse. Its origin does not appear to have any common root with the modern word "grey" for color, and indeed the Greyhound is seen with a wide variety of coats. Until the early twentieth century, Greyhounds were principally bred and trained for coursing. During the early 1920s, modern Greyhound racing was introduced into the United States and introduced into United Kingdom and Ireland in 1926.