portmanteau n.

["person who carries"] late 14c. (mid-13c. as a surname), portour, "person who carries" (goods, burdens), especially one who carries burdens or runs errands for hire, from Anglo-French portour, Old French porteor "porter, bearer; reporter" (12c.), from Late Latin portatorem (nominative portator) "carrier, one who carries," from past participle stem of Latin portare "to carry," from PIE root *per- (2) "to lead, pass over."

Old English mentel "a loose, sleeveless garment worn as an outer covering, falling in straight lines from the shoulders," from Latin mantellum "cloak" (source of Italian mantello, Old High German mantal, German Mantel, Old Norse mötull), perhaps from a Celtic source, or, if the Latin word is the same word as mantelum, mantelium "a cloth, hand-towel, napkin," perhaps it is from manus "hand."

Reinforced and altered 12c. by cognate Old French mantel "cloak, mantle; bedspread, cover" (Modern French manteau), also from the Latin source. Figurative sense "that which enshrouds, something that conceals, a covering" is from c. 1300. Allusive use for "symbol of literary authority or artistic pre-eminence" (by 1789) is from Elijah's mantle (II Kings ii.13). As a layer of the earth between the crust and core (though not originally distinguished from the core) it is attested from 1940. To take (originally have) the mantel (and the ring) was a symbolic act done before a bishop by a widow, indicating a vow of chastity (c. 1400).

1905, a blend of smoke (n.) and fog (n.), formed "after Lewis Carrol's example" [Klein; see portmanteau]. Reputedly coined in reference to London, and first attested there in a paper read by Dr. H.A. des Voeux, treasurer of the Coal Smoke Abatement Society, though he seems not to have claimed credit for coining it.

At a recent health congress in London, a member used a new term to indicate a frequent London condition, the black fog, which is not unknown in other large cities and which has been the cause of a great deal of bad language in the past. The word thus coined is a contraction of smoke fog "smog" — and its introduction was received with applause as being eminently expressive and appropriate. It is not exactly a pretty word, but it fits very well the thing it represents, and it has only to become known to be popular. [Journal of the American Medical Association, Aug. 26, 1905]

Smaze (with haze (n.)) is from 1953.