A listener asked for the term for a person who uses large words when smaller ones would do. Much to our delight, we were unable to find a term naming such a person (that is, with the exception of windbag and blowhard, but those aren't precise matches). However, our lexicon is riddled with terms naming that sort of discourse. (来源：英语学习门户 http://www.EnglishCN.com)

We've talked before about fustian and bombast. Both those words originally referred to fabrics: bombast named any soft fibrous material used as padding or stuffing, and fustian to a cotton with a pile face. Applied to language, bombast names verbose grandiosity or pretentious inflation of language and style disproportionate to thought, while fustian may suggest a filling or padding with the sonorous or grandiloquent (but inane).

Other terms that come to mind are prolix (which strongly implies tediousness through attention to minute detail that extends the matter beyond all due bounds) and verbose, used to suggest an overabundance of words as a literary or rhetorical fault.

But our favorite descriptive word dates back more than 18 centuries, and is now archaic. Back in the 2nd century, Greek satirist Lucian featured, in a dialogue, a particularly bombastic speaker named Lexiphanes. No longer in common use, lexiphanic means "using ostentatiously recondite words."