Square Knot. Interlacing and securing of two ropes crossing at right angles. An 'S'-shaped bight is put in one rope; second rope interlaces the 'S' at right angles.
Square Rig. That rig in which the principal sails are bent to yards across the masts. 2. In Royal Navy, the name is colloquially given to the bluejackets' uniform - to distinguish it from the 'fore and aft' rig of petty officers.