User:ThoughtIdRetired/sandbox/10

Definitions
"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)"

"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."

"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."

Other terminology
"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.