In English speaking countries, a double-barrelled name is a family name with two parts, often joined by a hyphen, for example Appleby-Smythe. Famous people with such names include Jackie Joyner-Kersee.
A double-barrelled name will sometimes be chosen by a couple who do not wish to lose the family name of either the bride or the bridegroom, but do wish to mark their marriage with a union of their names.
Double-barrelled names tend to be fairly long, and are seen by some as inconvenient. Children who inherit a double barrelled name sometimes choose to stop using half of it (usually their mother's maiden name), especially when they marry.
Some names may also linked without a hyphen, e.g. Maynard Smith, Duncan Smith. One notable example of this today is Andrew Lloyd Webber, whose family name is Lloyd Webber.