sesquipedalian

"His sesquipedalian style made even simple ideas hard to understand."

"The professor's sesquipedalian lectures often left students confused."

"She loved using sesquipedalian terms to impress her friends."

"As a true sesquipedalian, he often bewildered his audience with unusual vocabulary."

"Her sesquipedalian tendencies made her a unique figure in the literary community."

"The sesquipedalian spoke in such complex terms that few could follow along."