1584, "traveling case or bag for clothes and other necessaries," from M.Fr.
portemanteau "traveling bag," originally "court official who carried a prince's mantle" (1547), from
porte, imperative of
porter "to carry" (see
porter (1)) +
manteau "cloak" (see
mantle).
Portmanteau word "word blending the sound of two different words," is 1882, coined by Lewis Carroll for the sort of words he invented for "Jabberwocky," on notion of "two meanings packed up into one word."