Magniloquent

I don't doubt he's very smart, nevertheless he's very boastful and magniloquent.

There is no doubt that the ordinary reader would enjoy, and he certainly would profit much by, a revival of the classic work—if only he did not fall asleep over its magniloquent but perissological otiosity.

The sermonizer, said Dwight [Macdonald], was guilty of "puerile, stupid twaddle" and seemed to have "a remarkable power of hypnotizing himself with magniloquent platitudes."