Grandiloquent
Etymology
From Latin "grandiloquus", from "grandis" (grand, great) and "loqui" (to speak). The word literally means "grand-speaking," and it has almost always carried a sneer: to be grandiloquent is to reach for grandeur in one’s manner of speaking, whether or not the substance earns it.
adjective · /gran-DIL-uh-kwunt/
Using lofty, high-flown, or pompous language.
What it names
An inflated speaking style — big words and grand phrasing — with a built-in note of disapproval for showing off.
Example
His grandiloquent toast ran ten minutes and left the newlyweds unsure what he had actually wished them.
Related idea
Grandiloquent describes the lofty, showy style of speaking; bombast names the emptiness that often fills it — grandiloquence is the manner, bombast the hollow content that frequently rides along with it.