Foresail
A sail set forward of a vessel’s mainmast.
On many modern fore-and-aft-rigged sailing boats, the word refers generally to a headsail such as a jib or genoa. The sail is normally set from the forestay or from another stay or spar ahead of the mainmast.
Traditional square-rig terminology is more specific: the foresail is the lowest square sail on the foremast. The intended meaning therefore depends on the vessel’s rig and context.
