What does the idiom tongue-in-check mean?

The idiom "tongue-in-cheek" means to say something that is not meant to be taken seriously or literally. It implies that the speaker is being humorous or sarcastic, and that their words should not be interpreted as a sincere statement.

Here are some examples of how "tongue-in-cheek" might be used:

* "I'm so excited to go to work tomorrow," she said tongue-in-cheek. (She actually hates her job)

* "The traffic was awful, but at least I got to enjoy the scenery," he said tongue-in-cheek. (He was actually very frustrated with the traffic)

* "I'm so glad I won the lottery, now I can finally afford to pay my rent," he joked tongue-in-cheek. (He did not win the lottery)

The idiom is often used to lighten the mood or add a bit of humor to a situation. It can also be used to express a subtle form of criticism or disapproval.