A portmanteau is a traveling case or bag for clothes and other necessaries, on a notion of being carried by a porter. Portmanteau word forming was coined by Lewis Carroll on the notion of "two meanings packed up into one word." i.e. Motel comes from morphing motor and hotel. A magician, it seems to me, might use this portmanteau nonsense technique with things. i.e. Transforming coffee beans into a coffee cup or vice visa.