Definitions

1. noun

a unit of length, equivalent to 220 yards or 201.17 metres, used to measure distances, especially in horse racing

“The horse ran a furlong in 15 seconds, a remarkable time for its age.”

2. verb

to shorten or reduce something, especially a sail, to a smaller size or area

“The sailor had to furl the sail to prevent it from being torn in the strong wind.”