Definition & Meaning of "with {one's} tongue in {one's} cheek"

What is the origin of the idiom "with one's tongue in one's cheek" and when to use it?

The origin of the idiom "with one's tongue in one's cheek" can be traced back to the physical gesture of placing one's tongue inside the cheek while speaking. This gesture is associated with hiding one's true feelings or intentions while saying something, often in a sarcastic or ironic manner. This idiom is used informally to indicate that someone is speaking with a touch of irony, sarcasm, or insincerity. When someone makes a statement "with their tongue in their cheek," it means that they may not be entirely serious about what they are saying, and there is a playful or mocking element to their words. It's a way of signaling to the listener that the statement should not be taken at face value.