When an article of clothing is said to be "bespoke", then this means that the piece of clothing was custom made for a specific client. Bespoke clothing is different from tailored or ready-to-wear clothing. For Bespoke clothing an item is 100% created from scratch to fill a specific order for a specific client; whereas tailored or ready-to-wear items make use of a pre-existing and mass-produced articles of clothing.
In fashion the term bespoke is used exclusively for men’s clothing that has been custom made to order (for women's clothing the term would be haute couture).
The origins of the word bespoke come from the similar word bespeak (to ask for, or reserve, in advance). While the term bespoke is quite commonly used in European countries it has not reached the same level of international usage as the female analogue of haute couture.
Due to the increased quality of ready-to-wear items that can be tailored quickly the popularity of bespoke clothing is currently in decline. While there is a dedicated consumer base for this level of service they are getting older, and many tailors who specialize in bespoke suits are having difficulties attracting a new generation of clients.