The word portmanteau shows up in a lot of the literature I read for school assignments. It sounds French. What does it mean?

Portmanteau, which you pronounce as port-man-toe, originates in the French language and translates to "carries the cloak." You can spot the word in many literary works, including The Three Musketeers, Great Expectations, Jane Eyre, War and Peace, Don Quixote, Dracula, and Frankenstein.

You are likely to own a form of a portmanteau to carry your own modern-day cloak, along with other clothes, when you travel. Traditionally made of leather, a portmanteau can be crafted of any covering to serve its purpose as a suitcase. Typically, the bag or case opens to give you two equally spacious compartments for packing your belongings.

From George Eliot's Adam Bede:

As he reached the foot of the slope, an elderly horseman, with his portmanteau strapped behind him, stopped his horse when Adam had passed him, and turned round to have another long look at the stalwart workman in paper cap, leather breeches, and dark-blue worsted stockings.