puffed up with vanity; "a grandiloquent and boastful manner"; "overblown oratory"; "a pompous speech"; "pseudo-scientific gobbledygook and pontifical hooey"- Newsweek
lofty in style; "he engages in so much tall talk, one never really realizes what he is saying"
disapproval Grandiloquent language or behaviour is very formal, literary, or exaggerated, and is used by people when they want to seem important. using words that are too long and formal in order to sound important = pompous (grandiloquus, from grandis ( GRAND) + loqui )