a stuffed shirt
Someone who is very formal, pompous, or old-fashioned. I had heard he was a bit of a stuffed shirt, but he was very pleasant when I met him, and not pretentious at all.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
a stuffed shirt
If you call a man a stuffed shirt, you mean that he is formal and boring. His seminars work because he speaks like an ordinary, approachable person rather than a stuffed shirt. It's his amusement about the world around him that makes him appealing as a politician, so different from all those stuffed shirts. Note: You can use stuffed-shirt before a noun. I have little patience with the dress rules of stuffed-shirt establishments. Note: This refers to a shirt being displayed on a dummy in a clothing shop. The dummy is hollow and has no use apart from filling the space occupied by the shirt.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012
a stuffed ˈshirt(informal, disapproving) a person who is very serious, formal or old-fashioned: This office is full of stuffed shirts; there’s no one fun that I can have a laugh with.
Farlex Partner Idioms Dictionary © Farlex 2017
stuffed shirt, a
A pompous, self-satisfied, rigid person. Shakespeare had the idea in Much Ado about Nothing (1.1), “He is no less than a stuffed man,” implying that this person was so full of himself that he was, in fact, quite empty. The current cliché, which dates from about 1900, calls up the image of a shirt filled with tissue paper or some other material, which then appears to have a live person in it but actually does not.
See also: stuff
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer