An academic or pseudo-intellectual who uses convoluted phrases in order to intimidate the lay person, ostentate his or her position, and possibly, disguise the fact that they have nothing of any importance to say, is commonly called a windbag.
If you are looking for a fancier term for verbosity, I present pressologia
Perissology means using more words than necessary to explain one’s
meaning, a pleonasm. Since perissology is three letters longer than
pleonasm but means the same, you may argue it’s an example of the
related habit of using long words when shorter ones will do.
In A Dictionary of Literary Devices: Gradus, A-Z by Bernard Marie Dupriez, we learn that it is indeed a tactic, a form of strategy for filling an empty page or moments of silence. However, as I understand it, it needn't be incomprehensible.
pressology is one of the principle devices used by the media in their production of filler or padding
A similar rhetorical device is battology, which Richard Nordquist defines as "A rhetorical term for needless and tiresome repetition in speaking or writing". It reminds me of the Italian verb battere and gerund form battendo, which can be translated to hammering, and the English idiom to beat around the bush when someone is deliberately being evasive or unclear.
But the best word I found, and one which didn't have me scrambling for my dictionary, is the pejorative and informal term academese.
Academese is characteristic of academicians who are writing for a
highly specialized but limited audience, or who have a limited grasp
of how to make their arguments clearly and specifically" (Garner's
Modern American Usage, 2009).
A further example of academese is provided here, the words which I have placed in bold are the academese expressions.
Vernacular Equivalents to Academese
"[E]ffective academic writing tends to be bilingual (or 'diglossial'),
making its point in Academese and then making it again in the
vernacular, a repetition that, interestingly, alters the meaning. Here
is an example of such bilingualism from a review of a book on
evolutionary biology by a professor of ecology and evolution, Jerry A.
Coyne. Coyne is explaining the theory that males are biologically
wired to compete for females. Coyne makes his point both in Academese,
which I italicize, and in the vernacular, staging a dialogue in the
text between the writer's (and the reader's) academic self and his
'lay' self: 'It is this internecine male competitiveness that is
assumed to have driven not only the evolution of increased male body
size (on average, bigger is better in a physical contest), but also of
hormonally mediated male aggression (there is no use being the biggest
guy on the block if you are a wallflower).'
source: Gerald Graff, Clueless in Academe: How Schooling Obscures the Life of the Mind. Yale Univ. Press, 2003
Best Answer
We had one on the door when I was growing up in the 1960s London and we called it the Vassi. Just checked with my sister and she remembers the same word. Never knew why until I read Hans Adler comment. It was clearly a corruption of vasistas. It was my Grandmother's word as it was her house.