Building vocabulary via blending

Twisty Tongue recently told readers that “smog” is a portmanteau word.
Portmanteau word is a term coined by Lewis Carroll (1832-1898) in, Through the Looking-Glass (1871). In that book, Humpty Dumpty explains that “slithy,” found in the poem, Jabberwocky,  comes from slimy and lithe and is a portmanteau word. He tells Alice it’s called that because it’s like, “A two-part portmanteau bag” (a suitcase with two compartments).
Portmanteau is used by linguists although the preferred label for words like slithy is “blend.”
Oxford notes that the source words, slimy and lithe are difficult to identify in Carroll’s new word, and adds, “Some blends follow clear-cut boundaries as in Oxbridge from Oxford and Cambridge.”
Blending is increasingly used today to create new words. Thus, we have Chunnel from channel and tunnel; heliport  from helicopter and airport; brunch from breakfast and lunch; motel from motor and hotel; and smog from smoke and fog.
Occasionally, the portmanteau’s elements are separated. That is, they aren’t attached to form a single
unbroken word. So, we have creations like hi-tech and CompuSex. Nevertheless, most portmanteaux are single entities.
Some portmanteaux are so embedded in English we’ve forgotten they are blends. Electrocute (electric and execute) has been with us since the 1880s. Motorcade (motor and cavalcade) has been around since 1913. Breathalyzer (1954) originated in breath and analyze.
Dumfound (1653) is from dumb and confound. Outpatient (1715) melds outside and patient.
Some blends form proper nouns. The name, Pakistan is a combination of the first letters of Punjab, Afghan, Kashmir, Sind, plus the ending of Baluchastan. Kenora, once called Rat Portage, uses the first two letters of Keewatin, Norman, and Rat Portage. Texarkana, Arkansas, blends Texas and Arkansas. The pottery known as Medalta was named by blending Medicine Hat and Alberta’s abbreviation, Alta.
A building in Washington, D.C., called Watergate housed the national headquarters of the Democratic Party. It was bugged and burgled by members of the Republican Administration. The ensuing scandal resulted in President Richard M. Nixon’s resignation.
Even while this nasty affair was still unfolding, journalists started to attach gate to scandals of all sorts. This practice continues today. Canadians recently heard of Senategate and Duffygate. Similar blends are Irangate and Camillagate.
Medicare (medical and care), laundromat (laundry and automat), infomercial (information and commercial), blog (web and log), sitcom (situation and comedy) hassle (haggle and tussle), travelogue (travel and monologue), paratroops (parachute and troops), and cellophane (cellulose and diaphane), are all portmanteaux that are here to stay.
But evailable (electronic/available), chillax (chill/
relax), ridonkulous (ridiculous/donkey), and vidiot (video/idiot) are probably here today and gone tomorrow. So, too, are words like sportsational (sports/sensational) and swimsational (swim/sensational).
As film stars sink into oblivion, so will blends derived from their names. So long Brangelina. We won’t miss you.
Names given to animals that are themselves blends (hybrids) are well-established — beefalo (beef/buffalo), liger (lion/tiger), cockapoo (cocker spaniel/poodle).
Anyone can make up a word, but that word must fill a need before it actually enters our language. Words like Chunnel and smog actually do that.