The Collaborative International Dictionary of English v.0.48:

Portmanteau \Port*man"teau\, n.; pl. Portmanteaus. [F.
   porte-manteau; porter to carry + manteau a cloak, mantle. See
   Port to carry, and Mantle.]
   A bag or case, usually of leather, for carrying wearing
   apparel, etc., on journeys. --Thackeray.
   [1913 Webster]