If someone is asked to “keep their shirt on,” that means they should keep calm.
This phrase is basically another way of saying “calm down” and is often used in heated situations where another person is riled up.
Example: I borrowed a friend’s car to go grocery shopping. As I returned with a cart full of groceries, I accidentally scraped the side of his vehicle with my shopping cart. Needless to say, it left a big scratch. I told my friend about what happened and he got upset with me, so I told him to keep his shirt on because I would fully cover the damage costs.
In other words, the agitated friend was told to calm down; to relax.
The Origin Of ‘Keep Your Shirt On’
The origin of this phrase is unclear. However, it probably has something to do with how when people get so angry that they want to fight, they will sometimes remove their shirt before doing so. But why do they take off their shirt?
Well, it’s probably because shirts can restrict a person’s movements to an extent, especially if it’s a tighter fitting one. By removing the shirt, it allows for further range of motion of the upper body that would otherwise be limited. Basically, think about if you wore a pair of jeans that were too small. Obviously, you could still move around in them, but your legs would certainly be restricted in terms of the range they can move at. The same applies for shirts, just not to such an extreme degree.
Anyways, like I said, the origin of this phrase likely comes from angry people and how they react sometimes by taking off their shirt. Someone who is not interested in fighting would want them to literally keep their shirt on.
Now, let’s talk about when this phrase started to appear in print with its figurative meaning. It’s earliest known appearance (that I could find, anyways) is from the late 19th century, and I have two examples to show. The first is from the Geelong Advertiser newspaper, printed on June, 1894:
“Now young man, you keep your shirt on, and don’t be too smart.”
The second example is from the Melbourne Punch newspaper, June 1892. There’s a part from it that reads:
“‘Keep your shirt collar on, Gladdy,’ says I.”
- Several people around me became irritated after an elderly woman cut in line at the grocery store, so I told them to keep their shirts on and that if they had a problem with it, they should go ask her nicely to move to the back of the line.
Note: The origins for many popular sayings and expressions cannot be said with a certainty. So what’s provided on a page in such cases are theories that talk about how a phrase may have originated. However, if no theory exists, then the earliest known recording of the phrase in print will included (typically). These recordings are there to give you an idea on how old an expression is.
If there is an older recording of a phrase than what I have listed on the page, then go ahead and keep that shirt on and, if you’d like, let me know via e-mail.