A furlong is a British measure of distance, apparently used for measuring fields and related to the distance a horse could plough at once: 660 feet or 201.168 m. The name "furlong" is a contraction of "a furrow long". There are 8 furlongs in a British mile. Distances less than a mile for thoroughbred horse races in the United States are given in furlongs, but the unit is otherwise no longer much used.

Coincidentally, since a kilometre is about five-eighths of a mile, it is also about five furlongs.

Trivia