Macaronism is a noun that refers to the excessive use of big, showy words in writing or speech. 

Originally coming from French, macaronism was used in the 17th century to refer to the excessive use of foreign words for the sake of sounding sophisticated and learned. In time it came to mean any showy or extravagant use of words. Here’s an example:

Daryl’s macaronism has really gotten out of hand. It’s reached the point where he can’t even say “good morning” in less than ten minutes.