The man in the bespoke suit is likely to be either the best-dressed or the most overdressed person at your backyard barbecue, depending on how you look at it. Bespoke means custom-made.
Clothing that's made to order, tailored especially for you, is called bespoke. It's an adjective that is more common in Britain than in the United States. Bespoke can also describe non-clothing items that are made-to-order, as well as the person who makes such things: a bespoke jeweler. The term was originally bespoken, meaning "spoken of or arranged beforehand." Obviously, if you wanted a custom-made suit, you had to make arrangements before buying it.