bloviate

From Dictionary.com

bloviate \BLOH-vee-ayt\, intransitive verb:
To speak or write at length in a pompous or boastful manner.

Bloviate is from blow + a mock-Latinate suffix -viate. Compare blowhard, "a boaster or braggart." Bloviation is the noun form; a bloviator is one who bloviates.

Trivia: Bloviate is closely associated with U.S. President Warren G. Harding, who used it frequently and who was known for long, windy speeches. H.L. Mencken said of him, "He writes the worst English that I have ever encountered. It reminds me of a string of wet sponges; it reminds me of tattered washing on the line; it reminds me of stale bean soup, of college yells, of dogs barking idiotically through endless nights. It is so bad that a sort of grandeur creeps into it. It drags itself out of the dark abysm of pish, and crawls insanely up the topmost pinnacle of posh. It is rumble and bumble. It is flap and doodle. It is balder and dash."