Bloviate means to speak or write at length in a pompous, boastful, or empty way.  The verb comes from the American slang word blow (meaning "to boast" or "speak idly," as in blowhard) combined with a mock-Latin suffix (-i- plus -ate), modeled after real Latin-derived English verbs like deviate or abbreviate.  The fake Latin ending was added to give the word a humorous, self-important sound that mirrors the pretentious style of speaking it describes.  

According to the Oxford English Dictionary (OED), the earliest known use of the verb bloviate in English is from 1845, appearing in the Huron Reflector newspaper published in Norwalk, Ohio.  Though often mistakenly credited to H.L. Mencken or President Warren G. Harding, Harding famously used and popularized the term during the presidential campaign in the 1920s to describe long-winded, empty speech.

59 minutes ago, drpaladin said:

My mind shuts off when I encounter bloviating.

A lot of us seem to be walking around in a fog these days.