The expression “Three Sheets to the Wind” means very drunk. You must be wondering on the relation between sheets and drunkenness. Well, it refers to the origin of the expression which has its roots in nautical history. It refers to ships whose sails are not secured properly by the sheets causing the ship to sway out of control and stagger like a drunken sailor. The earliest use of the phrase is “three sheets in the wind” as found in 1821 in Pierce Egan’s work, “Real Life in London”. More recently “Three Sheets” was the name of a TV show which was derived from the phrase “Three Sheets to the Wind”.
The phrase "Three Sheets to the Wind" has its origin in the sailor’s terminology and was essentially a seafaring expression. The sheets however do not refer to the sails but are ropes used to keep the sails in place. It generally took three ropes to secure the sails firmly to the ship. The sheets are fixed to corner of the sails but if the three sheets are not fixed properly and blow in the wind then the ship is likely to sway like a sailor who is very drunk and staggering.
If one sheet is not fixed properly the sail may lightly flap but the ship may be relatively stable. In case of two sheets becoming loose the ship may find it difficult to maintain its straight course but losing “Three Sheets to the Wind” would cause the ship to sway and wobble like a sailor who is completely drunk and intoxicated. “Four sheets in the wind” would mean that the ship is literally out of control.
The state of the person who is very drunk is described as “Three Sheets to the Wind” and is akin to the ship which has three of its sheets flapping loosely in the breeze. Both the drunken person and the ship are in an unstable state and literally beyond control. Sailors in the earlier days measured the degree of their drunkenness on the basis of the sheets. “One sheet in the wind” implied that the sailor was in a tipsy state while “Three Sheets to the Wind” indicated the extreme drunkenness of the sailor who is in the falling over stage.