yardarm

Yardarm is a compound: yard (a horizontal spar from which a sail hangs) + arm (the outer end of it). The 'yard' comes from Old English gierd (a rod, a staff, a measuring stick), which is also the origin of 'yard' as a unit of measurement (three feet) and 'yard' as an enclosed outdoor space. The yardarm is specifically the outer portion of the yard — the end that extends beyond the mast on each side of the ship.

Yards are the horizontal beams that cross the masts on square-rigged ships. The main yard on a large sailing ship could be over 100 feet long. Sailors worked on the yards at heights of 100 feet or more, standing on footropes (ropes stretched beneath the yard) while handling heavy, wet canvas. Falls from the yardarm were a leading cause of death on sailing ships. 'Learning the ropes' was literally learning which ropes to pull, and the yardarm was where many of them led.

The expression 'the sun is over the yardarm' — meaning it is late enough to drink — originated in the Royal Navy. When the sun had risen high enough to clear the upper yardarm (roughly 11 AM at the latitudes the British fleet typically operated), officers were permitted their first drink of the day. The yardarm became a sundial for alcohol. The angle of the sun to the spar told the time.

Pirates and naval courts executed prisoners by hanging them from the yardarm. The practice gave the yardarm a grim secondary association. The same beam that held sails also held ropes with nooses. The word carries both the beauty of sail and the brutality of punishment.