1 A board or reach sailed in a sailing vessel with the wind kept on one side of the vessel. See also leg; port tack; starboard tack.
2 The name given to the lower forward corner of a sail in a fore-and-aft rig.
3 In square-rigged sailing ships, it is the name of the rope used to hold in the weather lower corners of courses and staysails when sailing close hauled. Also, when studding sails were set, it was the name given to the rope employed to haul out the lower outer clew of the sail to the end of the boom.
4 When used as a verb, it describes the operation of bringing a sailing vessel head to wind and across it so as to bring the wind on the opposite side of the vessel.