furlong [OE] Old English furlang is from furh ‘furrow’ and lang ‘long’, and meant the standard length of a furrow in a common field, which was regarded as a nominal square of ten acres. It was also used as the equivalent of the Roman measurement the stadium, one eighth of a Roman mile, which gave rise to the current sense. Stadium came from Greek stadion ‘race track’ and stadium came to be used in this sense in the early 17th century, with sports stadium appearing in the mid 19th century.