Haute couture (French for “high sewing” or “high dressmaking”; pronounced [oːt kuˈtyʁ]) refers to the creation of exclusive custom-fitted fashions. It originally referred to Englishman Charles Frederick Worth’s work, produced in Paris in the mid-nineteenth century. In modern France, haute couture is a “protected name” that can be used only by firms that meet certain well-defined standards. However, the term is also used loosely to describe all high-fashion custom-fitted clothing, whether it is produced in Paris or in other fashion capitals such as Milan, London, Rome, New York and Tokyo. Haute couture is made to order for a specific customer, and it is usually made from high-quality, expensive fabric and sewn with extreme attention to detail and finish, often using time-consuming, hand-executed techniques.
The term can refer to:
-the fashion houses or fashion designers that create exclusive and often trend-setting fashions
-the fashions created

Source: Wikipedia.

So ladies next time you hear a celebraty say “its some designer ‘Couture'” it means it was custom made from the designer to that person.