Definition of mainsail in US English:

mainsail

noun

  • 1The principal sail of a ship, especially the lowest sail on the mainmast in a square-rigged vessel.

    • ‘As the galley righted itself, another wave struck from the other side, and the ship heeled over so far its mainsail almost touched the water.’
    • ‘These days, the majority of new mainsails are designed with a loose-footed arrangement.’
    • ‘These mainsails are the more traditional mainsail cut with short length battens and slab reefing.’
    • ‘While the mainsail provides a large portion of power, it also affects the boat's directional control.’
    • ‘Hornblower watched as both ships backed the mainsails, turned the helm hard over, and took up the prescribed position.’
    1. 1.1 The sail set on the after side of the mainmast in a fore-and-aft-rigged vessel.

Pronunciation