you guys are on the wrong track; the word is pronounced /POSH lust/, which makes a lot more sense anyway.
I lifted the following out of a google/Gogol cache of a now seemingly dead link (thus the lack of proper attribution):

I'm reading Nikolai Gogol's Dead Souls, which is quite humorous in it's look at
banality. But it's more than just banality, according to the introduction:
The word translated as "banality" here is the Russian poshlost. For a full
comprehension of the meaning of poshlost (pronounced "POSHlust"), readers are
referred to Vladimir Nabokov's Nikolai Gogol (1944), which contains a twelve-page
disquisition on the subject. Poshlost is a well-rounded, untranslatable whole made
up of banality, vulgarity, and sham. It applies not only to obvious trash (verbal and
animate), but also to spurious beauty, spurious importance, spurious cleverness. It
is an ideal subject for Gogolian treatment, a "gape in mankind," as he calls
Plyushkin, an absence he can bring to enormous presence by filling it with verbal
matter. Gogol's portrayal of poshlost goes far beyond topical satire or a
denunciation of social evils. His characters are not time bound; they inhabit an
indefinitely expanded time in which they lose the sharply negative features of vice
and wickedness and instead become wildly funny. They also have no psychology,
no "inner nature."