“Tongue-in-cheek” is a saying that is used to describe something that was intended as a joke; not serious.
This phrase may have been made up by an English humorist in the mid-1800s. You would have difficulty saying anything with your tongue in your cheek. Some people actually do poke their cheek with their tongue after making an insincere remark to show they were only kidding. It’s a facial expression similar to winking after saying something that’s meant to be taken as a joke.
Here is an example sentence using the phrase “tongue-in-cheek”:
“You shouldn’t be insulted by what Rose said because she meant it tongue-in-cheek.”