A portmanteau is a type of what accessory?

A portmanteau is a piece of luggage, usually made of leather and opening into two equal parts. Some were large, upright, and hinged at the back and enabled hanging up clothes in one half, while others are much smaller bags (such as Gladstone bags) with two equally sized compartments. The word derives from the French word portemanteau (from porter, "to carry", and manteau, "coat"), which nowadays means a coat rack but was in the past also used to refer to a traveling case or bag for clothes.

A Gladstone bag is a small portmanteau suitcase built over a rigid frame which could separate into two equal sections. Unlike a suitcase, a Gladstone bag is "deeper in proportion to its length." Gladstones are typically made of stiff leather and often belted with lanyards. The bags are named after William Ewart Gladstone (1809–1898), the four-time Prime Minister of the United Kingdom.