To tremble; said of sails when a boat is headed in a direction too close to the wind
1 The forward edge of a sail 2 To alter course so that the boat sails closer to the wind or turns into the wind 3 A sail luffs when the wind backs it close to the luff, i e when the boat is pointed too close to the wind or when the sail is not trimmed in far enough
sailing close to the wind flap when the wind is blowing equally on both sides; "the sails luffed" sail close to the wind In a lucky manner; by good fortune; fortunately; used in a good sense; as, they luckily escaped injury
To alter the vertical angle of the jib of a crane so as to bring it level with the load