swallowing the dictionary

Verb

swallow the dictionary (third-person singular simple present swallows the dictionary, present participle swallowing the dictionary, simple past and past participle swallowed the dictionary)

1. (idiomatic, informal) To speak using long or obscure words.
   • I swear, I don't know where you get all this swallowing the dictionary business!” - He himself never read anything but the ticker and the sporting news.1918, The Saturday Evening Post - Volume 190, page 5