"Square sail. Sails set from yards that can only be trimmed on the fore side of mast, thus always presenting same surface of sail to wind (unless aback)" [1]: 240
[2]: 2
"Square rig The type of rig which uses four-sided sails hanging beneath yards which are suspended from the mast at their midpoints. There is thus an equal area of sail each side of the mast, whereas the ‘fore-and-aft’ rig sets all, or nearly all, the sail to one side of the mast." [3]
"Squaresail An approximately rectangular sail which is set on a Yard so that its centreline coincides with the mast. Other four-sided sails such as the Gaff, Sprit-sail and various Lugs are set entirely or mainly to one side of the mast." [3]
"Square by the lifts" – when the yards are perpendicular to the mast, so, horizontal if the ship is not heeled.
"Square by the braces" – when the yards are perpendicular to the fore and aft line of the hull.
"Square by the lifts and braces" – when the yards are perpendicular to the plane of the keel.
[4]: 647
"Square sail. Sails set from yards that can only be trimmed on the fore side of mast, thus always presenting same surface of sail to wind (unless aback)" [1]: 240
[2]: 2
"Square rig The type of rig which uses four-sided sails hanging beneath yards which are suspended from the mast at their midpoints. There is thus an equal area of sail each side of the mast, whereas the ‘fore-and-aft’ rig sets all, or nearly all, the sail to one side of the mast." [3]
"Squaresail An approximately rectangular sail which is set on a Yard so that its centreline coincides with the mast. Other four-sided sails such as the Gaff, Sprit-sail and various Lugs are set entirely or mainly to one side of the mast." [3]
"Square by the lifts" – when the yards are perpendicular to the mast, so, horizontal if the ship is not heeled.
"Square by the braces" – when the yards are perpendicular to the fore and aft line of the hull.
"Square by the lifts and braces" – when the yards are perpendicular to the plane of the keel.
[4]: 647