The situation of the sails of a square-rigged ship when the yards are trimmed to bring the wind to bear on their forward side. Sails are laid aback purposely to stop a ship's way through the water or to assist her in tacking; they are taken aback inadvertently when the ship is brought to by an unexpected change of wind or by the helmsman's lack of attention.
‘Lay all flat aback’ was the order in square-rigged ships to lay all sails aback in order to stop the ship and give her sternway. When lying at a single anchor such ships normally spread a mizzen topsail laid aback to prevent the vessel surging to the anchor and fouling it with her cable.
[a] Sails drawing
[b] Sails aback