Example: The groom made it to the alter, but he was three sheets to the wind.
Origin: The phrase comes from 18th-19th century English Naval terminology. The original phrase was "three Sheets in the wind" and referred to the erratic behavior of a ship that has lost control of all of its sails.
Sailors in danger of losing their lives created the phrase. Many old-time vessels performed best when rigging was symmetrical. Outfitted with four masts and four sets of sails, a craft was expected to use all of them under most circumstances. Sometimes, though, the fourth and final sets of canvas were not spread. A four-master with only three masts in action was in big trouble when hit by a sudden gale. The rolling and pitching of a poorly rigged ship was much like the actions of a human who downed too many drinks. A comparison was inevitable - a thoroughly drunk man barely able to get walk was described as lacking an essential set of canvas sails.