A phrase which means “very drunk.” Its origins are nautical but contested. In one version, the “sheets” refer to chains or ropes which attach the sails to the boat. For them to be “to the wind” means the ship is falling over itself in the manner of a drunk. This means that there was a scale of how many sheets to the wind one could be. But another explanation is that the sheets means sails, and the key is not that there are three because three is a lot of sheets, but that three is an odd number. Even numbers of sails would be balanced, but odd numbers would not be. I don’t know either is right. The second link references another NY Times article that is a quick and fun read.